live crash with big livest

[yaztrax]

hi!
i'm working on a big liveset who include actually something like 15 or 20 tracks (audio, midi, instruments, lots of vst plugins)
my cpu is working at 50-60 % when i play the set and perform live.

the problem is that i everytime experiment problems to load my last live set. The set don't want to open and the message " A serious program error has occured. Live will shut down ... "
So i lost my last changes and need everytime to go back to a previous file and this is a waste of time and hours of work...

I'm using vst instruments and when i play a note on my midi keyboard there is a lot of latency but my soundcard settings is on 10 ms , ///...

I have a intel Q 6600 quad core , 4 GB RAM, vista 32 bit, Emu 1212 m