I had a similar problem, maybe not exactly the same as yours. I'm running Snow Leopard with PD5.0 (latest build), no Bootcamp, Windows 7 Pro.
I could print from Win 7 but not from the Mac side. The problem turned out to be the Mac print driver was corrupted. I went to Apple.com and downloaded the printer driver set, reinstalled and everything works fine now.
Hope this helps.