Parallels XP max file size for iplayer

I'm running XP under Parallels Desktop 3.0. I'd like to use the bbc iplayer to download an odd program or two and watch it. On my xp laptop I can watch iplayer downloaded files with any old video player and they work fine - windows media player for example. On the mac attempts to watch one with anything - iplayer or WMP always crashes, in fact even trying to look at the directory where one is stored crashes windows explorer. I suspect its something to do with file size (such downloads may be typically 400M or 600M).

Anyone have any experience here and how I can get around the problem ?

andy