After upgrading to Mac OS X Lion, I booted into Windows 7 / Boot Camp and experienced constant Blue Screens of Death (BSODs). Windows would boot, but I'd only have a minute or two before getting a BSOD citing "cache_manager" as the culprit. The fix was to rename the Apple HFS driver, which can be found at:
After renaming that file and restarting (BSOD helped me to restart quickly!), Windows 7 became usable again. Note that this will prevent Windows from being able to see your Mac OS X file system (not a big deal, for me).
Source of fix: [Apple Support Communities](https://discussions.apple.com/thread/3264318)