EXS 24 Logic Sampler Users Group

....Hi.....
I'm not too advanced in Logic and EXS - recently instead of using my hardware 
instruments I'm using software more often and the problem is that I've got kinda 
half a second long latency effect .... what I mean is when I'm hit my keaboard I 
have to wait half a second to hear a sound from EXS or any other software 
instrument ...  I have no such a ploblem while plaing hardware .... I'm using 
Logic 5.5 on PC/Unitor midi
.... help GREATLY appreciated !!!!!!!! (can't play at all with current 
conditions)
Thanks