I've just experienced a very weird bug. After installing Dropbox 1.0RC over 0.7.112, my taskbar buttons have disappeared:
As you can see, none of the open programs have a button on the taskbar, so I have to alt-tab to switch. But win+n shortcut still works for the pinned programs. Changing various taskbar settings (position, grouping etc.) didn't help. I tried restarting explorer.exe and then rebooting. Didn't help. Turning off Dropbox and reinstalling it didn't help either, obviously.
UPDATE: Everything seems fine on a guest account; disabling Aero doesn't help, the buttons are not "hidden" by a toolbar.
I also think it's not a graphical glitch, because I tried most of the tips for the "missing taskbar" problem and nothing works. I simply don't have any buttons between the start orb and the tray.
UPDATE2: The problem still exists in safe mode.
UPDATE3: Command-line tool sfc didn't find any corrupted resources.
Is there a way to reset my user profile settings without destroying the whole profile?