Vegas-Make it Big- frequent short freezes

[MikeC]

I'm running VMIB under Windows XP with the latest game patch on a 3.0Gh P4/256MbRAM/128Mb video card which is all much higher spec than cited on the game box (ideal 700Mhz cpu/64mb RAM & 16Mb Video card RAM)
The problem is with the screen freezing often and for a second or two (sort of jerky). Is this a problem with the game or settings? As an example of other games the equipment runs the Sims with all the addons just fine with smooth walking of sim characters. Any ideas? I've tried the useless Compatibility route under XP trying to run it simulated for 2000/w98 etc but still no joy. Also changing screen resolution/unloading all apps etc.
Please help!