Importanta problem in ESS RC1

I've installed Eset Smart Security RC1. It's a cool programm, I really like it, BUT it crashes my computer.
I'm using Vista x64 and after my computer is on in some hours my PC just turns off without writing anything in the logs.
I can't determine what is the problem, but I remember when it crashed. 1st it crashed, while I played Counter-Strike. 2nd time it was when I was simultaniously downloading stuff by BitComet, converting .flac to .mp3 by Easy CD-DA Extractor, listening to music through Windows Media Player 11 and writing something in Microsoft Word. 3d time was as the previos one, but instead of Word I was using Maxthonfor surfering the Internet.
The most strange, that even when I was doing NOTHING it crashed my PC. Forthemore, it disabled somehow my ReadyBoost - I needed to re-pug-in the flash-card and formate it.
Maybe it's just the specific settings of my PC, but still I thought you should know, that there is such a problem. And, in case, you ask: after I uninstalled ESS crashing stopped. It's already 2 days of unstoppable working of my PC. Nothing has happend. So, try to figure out, what's crashing the system.
Thanks for your attention. And excuse me for my "Russian" English. (=