Nothing off the top of my head. You mean just activating it the site fails to render? That sounds like a header bug of some sort. Do the admin panels work?
Generally, blank pages are php errors that are occurring but aren't being shown/output due to php ini settings/etc. Couldn't say offhand any compatability issues, last I tried it was with 1.5, 1.5.1, 22.214.171.124, all fine, and did some testing on both Linux and Windows environments (apache & IIS). PHP4 and 5 environments. So nothing jumping out. Obv, meant to just drop in and work. ;)
You should feel free to ping me offline at cgcode at chait dot net if you want to discuss further, maybe we can put it through some tests late some night. I do have newer code than what's up on the site (I think!), but don't recall any major changes that cause/fix that.