I've been having this issue for over a week. I just noticed it, since I had to take my MBP (LAte 2008 2.4 MHZ unibody, 4gb) in to the Apple Store for a repair, and wanted to remove any passwords so the tech wouldn't have any problems working on it. I couldn't access the Accounts pane. It freezes for a bit, then the entire window closes, giving me the option to ignore or tell Apple about it. I had to remove the password from the Snow Leopard disk. I was told to remove the prefs file, the plist file, and cache files; nothing worked. I was told to reinstall a clean system. That didn't work, either. I upgraded using the combo updater to 10.6.7. Still no go. It even happened in front of the Genius at the Apple Store. He suggested removing the prefs, which I had already done, then recommended I do the clean install, which I later did (but wasn't effective.) I would hate to have to delete everything. Does anyone have any suggestions? I know that Apple had an issue w/an Accounts bug in Snow Leopard that deleted user info. Can this be related somehow?