Hi there.
I'm experiencing the exact same issue with one of the laptops I support. Here's my configuration:
MacBookPro 3,1 (Intel Core2 Duo)
Brand new installation of Leopard 10.5.4
Brand new installation of Windows XP Pro SP2 with all updates installed using Boot Camp
Leopard is bound to an OD server but all accounts are local ones
Parallels v3 build 5806
I've been doing some google searching about this issue, and I found a post from someone saying that they got this error after deleting a bunch of Login items which are apparently added by Parallels. I also know that binding a Mac to an AD or OD server can cause a weird crash/bug when accessing Login Items. But, after doing a Parallels install I didn't see anything added into the Login Items so maybe this is just a red herring.
I already have a ticket open, 557701 but from my past experience with the ticketing system, I'm not expecting any miracles. So in the meantime I put the installer on the users desktop and told him to reinstall every time he's done using Bootcamp.