Ilaplace and simplify and more roots

For numeric solution I use and it works:

s=ilaplace(result(i,1));
s=feval(symengine, 'float', s);
syms t 'real'
s=vpa(sqrt(2)*real(s),4);

but now I have problem with command simplify. If I use this command, than Matlab stop working, not responding.

s=simplify(s)

What is wrong?

[john]

Only during first calculation it takes aprox. 2 minutes. All next calculation take aprox 1 second?

Why?

Matlabu GUI has for it any memory? For results or what?

Thank you