Problem fuction feasp

I tried to run a program in MATLAB (2008b, 2010a, 2011a) with function "feasp" to solve a LMI but when i tried to run in a laptop using Windows Vista and processor Intel Core™2 Duo T5750 2.00Ghz 32-bit, the "tmin" value is negative for a infeasibility LMI problem. i had no problem in others computers with core solo and Windows XP. Program:

clear all; clc;

A = [1 1; 2 -2]; eig(A)

setlmis([]) P = lmivar(1,[2 1]); lmiterm([1 1 1 P],1,A,'s'); % LMI #1 lmiterm([-2 1 1 P],1,1); % LMI #2: P lmis = getlmis; [tmin,xfeas] = feasp(lmis); tmin

P = dec2mat(lmis,xfeas,P)

Program's answers:

tmin =

 -2.8468e-013

P =

1.0e+003 *

    0.7710   -1.3731
   -1.3731    2.4451