My experience is that something like PC2700 RAM on a motherboard rated for PC2100 isn't going to be a problem. I've never, in 15 years of home-built computers, had problems with memory that's faster than the minimum for the motherboard. Memory has been pretty stable for the last few years, in terms of physical format, just getting faster. And, if your motherboard can take it, at least think about going up to 1GB from 512MB. It's what I did last year. If it's heat-related, it could still be the hard drive. At least Poser is easy to shift between drives. Apart from file associations, so that you can click on a file to open it in Poser, it's just a copying problem; drag and drop and wait.