diff --git a/dynare++/sylv/matlab/gensylv.cpp b/dynare++/sylv/matlab/gensylv.cpp
index 9cfad4300..0a0d7e391 100644
--- a/dynare++/sylv/matlab/gensylv.cpp
+++ b/dynare++/sylv/matlab/gensylv.cpp
@@ -2,7 +2,7 @@
 
 /* Tag $Name:  $ */
 
-
+#include "dynmex.h"
 #include "mex.h"
 
 #include "GeneralSylvester.h"
@@ -13,14 +13,8 @@ void gen_sylv_solve(int order, int n, int m, int zero_cols,
 					const double* A, const double* B,
 					const double* C, double* X)
 {
-	try {
 		GeneralSylvester s(order, n, m, zero_cols, A, B, C, X, false);
 		s.solve();
-	} catch (const SylvException& e) {
-		char mes[1000];
-		e.printMessage(mes, 999);
-		mexErrMsgTxt(mes);
-	}
 }
 
 void gen_sylv_solve_and_check(int order, int n, int m, int zero_cols,
@@ -28,44 +22,18 @@ void gen_sylv_solve_and_check(int order, int n, int m, int zero_cols,
 							  const double* C, const double* D,
 							  double* X, mxArray*& p)
 {
-	try {
 		GeneralSylvester s(order, n, m, zero_cols, A, B, C, X, true);
 		s.solve();
 		s.check(D);
 		p = s.getParams().createStructArray();
-	} catch (const SylvException& e) {
-		char mes[1000];
-		e.printMessage(mes, 999);
-		mexErrMsgTxt(mes);
-	}
-}
-
-void checkDimensions(const mwSize* const Adims, const mwSize* const Bdims,
-					 const mwSize* const Cdims, const mwSize* const Ddims,
-					 int order)
-{
-	if (Adims[0] != Adims[1])
-		mexErrMsgTxt("Matrix A must be a square matrix.");
-	if (Adims[0] != Bdims[0])
-		mexErrMsgTxt("Matrix A and matrix B must have the same number of rows.");
-	if (Adims[0] != Ddims[0])
-		mexErrMsgTxt("Matrix A and matrix B must have the same number of rows.");
-	if (Cdims[0] != Cdims[1])
-		mexErrMsgTxt("Matrix C must be square.");
-	if (Bdims[0] < Bdims[1])
-		mexErrMsgTxt("Matrix B must not have more columns than rows.");
-	if (Ddims[1] != power(Cdims[0], order))
-		mexErrMsgTxt("Matrix D has wrong number of columns.");
 }
 
 extern "C" {
-	void mexFunction(int nhls, mxArray* plhs[],
+	void mexFunction(int nlhs, mxArray* plhs[],
 					 int nhrs, const mxArray* prhs[])
 	{
-		if (nhrs != 5)
-			mexErrMsgTxt("Must have exactly 5 input args.");
-		if (nhls !=1 && nhls != 2)
-			mexErrMsgTxt("Must have 1 or 2 output args.");
+		if (nhrs != 5 || nlhs > 3 || nlhs < 2 )
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Gensylv: Must have exactly 5 input args and either 2 or 3 output args.");
 
 		int order = (int)mxGetScalar(prhs[0]);
 		const mxArray* const A = prhs[1];
@@ -76,7 +44,20 @@ extern "C" {
 		const mwSize* const Bdims = mxGetDimensions(B);
 		const mwSize* const Cdims = mxGetDimensions(C);
 		const mwSize* const Ddims = mxGetDimensions(D);
-		checkDimensions(Adims, Bdims, Cdims, Ddims, order);
+
+                if (Adims[0] != Adims[1])
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Matrix A must be a square matrix.");
+                if (Adims[0] != Bdims[0])
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Matrix A and matrix B must have the same number of rows.");
+                if (Adims[0] != Ddims[0])
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Matrix A and matrix B must have the same number of rows.");
+                if (Cdims[0] != Cdims[1])
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Matrix C must be square.");
+                if (Bdims[0] < Bdims[1])
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Matrix B must not have more columns than rows.");
+                if (Ddims[1] != power(Cdims[0], order))
+                  DYN_MEX_FUNC_ERR_MSG_TXT("Matrix D has wrong number of columns.");
+
 		int n = Adims[0];
 		int m = Cdims[0];
 		int zero_cols = Bdims[0] - Bdims[1];
@@ -86,15 +67,25 @@ extern "C" {
 		ConstVector Dvec((double*)mxGetPr(D), power(m, order)*n);
 		Xvec = Dvec;
 		// solve (or solve and check)
-		if (nhls == 1) {
-			gen_sylv_solve(order, n, m, zero_cols,
+                try
+                  {
+                    if (nlhs == 2) {
+                      gen_sylv_solve(order, n, m, zero_cols,
 						   mxGetPr(A), mxGetPr(B), mxGetPr(C),
 						   mxGetPr(X));
-		} else if (nhls == 2) {
-			gen_sylv_solve_and_check(order, n, m, zero_cols,
+                    } else if (nlhs == 3) {
+                      gen_sylv_solve_and_check(order, n, m, zero_cols,
 									 mxGetPr(A), mxGetPr(B), mxGetPr(C),
-									 mxGetPr(D), mxGetPr(X), plhs[1]);
-		}
-		plhs[0] = X;
+									 mxGetPr(D), mxGetPr(X), plhs[2]);
+                    }
+                  }
+                catch (const SylvException& e)
+                  {
+                    char mes[1000];
+                    e.printMessage(mes, 999);
+                    DYN_MEX_FUNC_ERR_MSG_TXT(mes);
+                  }
+                plhs[1] = X;
+                plhs[0] = mxCreateDoubleScalar(0);
 	}
 };
diff --git a/dynare++/sylv/matlab/gensylv.m b/dynare++/sylv/matlab/gensylv.m
index b6cb0dccb..56f5f0e73 100644
--- a/dynare++/sylv/matlab/gensylv.m
+++ b/dynare++/sylv/matlab/gensylv.m
@@ -12,10 +12,11 @@
 %         ...... Kronecker power of C of order 'order'
 %       D .....  rectangular (n, m^order) matrix.
 %
-% X = gensylv(order, A, B, C, D)
-%       returns X as the solution, doesn't perform any checks
+% [err, X] = gensylv(order, A, B, C, D)
+%       returns err a scalar where 1 indicates failure, 0 indicates success
+%       and X as the solution, doesn't perform any checks
 %
-% [X, par] = gensylv(order, A, B, C, D)
+% [err, X, par] = gensylv(order, A, B, C, D)
 %       solves the system, and performs checks. 'par' is struct
 %       containing information about solution and error norms
 %       returned by the check. This is a list of the struct
@@ -52,7 +53,7 @@
 % $Header: /var/lib/cvs/dynare_cpp/sylv/matlab/gensylv.m,v 1.1.1.1 2004/06/04 13:01:13 kamenik Exp $
 % Tag $Name:  $
 
-function [X, varargout] = gensylv(order, A, B, C, D)
+function [err, X, varargout] = gensylv(order, A, B, C, D)
 
 % in Windows, ensure that aa_gensylv.dll is loaded, this prevents
 % clearing the function and a successive Matlab crash
@@ -63,12 +64,13 @@ if strcmp('PCWIN', computer)
 end
 
 % launch aa_gensylv
-if nargout == 1
+if nargout == 2
   X = aa_gensylv(order, A, B, C, D);
-elseif nargout == 2
+elseif nargout == 3
   [X, par] = aa_gensylv(order, A, B, C, D);
   varargout(1) = {par};
 else
-  error('Must have 1 or 2 output arguments.');
+  error('Must have 2 or 3 output arguments.');
 end
+err = 0;
   
\ No newline at end of file
diff --git a/matlab/dr1.m b/matlab/dr1.m
index 1323e6559..7996169d9 100644
--- a/matlab/dr1.m
+++ b/matlab/dr1.m
@@ -578,7 +578,8 @@ C = hx;
 D = [rhs; zeros(n-M_.endo_nbr,size(rhs,2))];
 
 
-dr.ghxx = gensylv(2,A,B,C,D);
+[err, dr.ghxx] = gensylv(2,A,B,C,D);
+mexErrCheck('gensylv', err);
 
 %ghxu
 %rhs
diff --git a/matlab/dr11_sparse.m b/matlab/dr11_sparse.m
index ad48a362e..41a5c2fda 100644
--- a/matlab/dr11_sparse.m
+++ b/matlab/dr11_sparse.m
@@ -332,7 +332,8 @@ C = hx;
 D = [rhs; zeros(n-M_.endo_nbr,size(rhs,2))];
 
 
-dr.ghxx = gensylv(2,A,B,C,D);
+[err, dr.ghxx] = gensylv(2,A,B,C,D);
+mexErrCheck('gensylv', err);
 
 %ghxu
 %rhs
diff --git a/matlab/gensylv/gensylv.m b/matlab/gensylv/gensylv.m
index 5ccacb271..16e0d559b 100644
--- a/matlab/gensylv/gensylv.m
+++ b/matlab/gensylv/gensylv.m
@@ -1,5 +1,5 @@
-function E = gensylv(fake,A,B,C,D)
-%function E = gensylv(fake,A,B,C,D)
+function [err, E] = gensylv(fake,A,B,C,D)
+%function [err, E] = gensylv(fake,A,B,C,D)
 % Solves a Sylvester equation.
 %
 % INPUTS
@@ -10,6 +10,7 @@ function E = gensylv(fake,A,B,C,D)
 %   D
 %    
 % OUTPUTS
+%   err      [double] scalar: 1 indicates failure, 0 indicates success
 %   E
 %    
 % ALGORITHM
@@ -18,7 +19,7 @@ function E = gensylv(fake,A,B,C,D)
 % SPECIAL REQUIREMENTS
 %   none.  
 
-% Copyright (C) 1996-2008 Dynare Team
+% Copyright (C) 1996-2010 Dynare Team
 %
 % This file is part of Dynare.
 %
@@ -38,3 +39,4 @@ function E = gensylv(fake,A,B,C,D)
 C  = kron(C,C); 
 x0 = sylvester3(A,B,C,D);
 E  = sylvester3a(x0,A,B,C,D);
+err = 0;
\ No newline at end of file