Hello
My problem is that I am seeing multiple devices(six to be exact) for my single Radeon HD 7750 card in Catalyst tray, where the dummy devices have other options except Extend desktop(which does nothing) greyed. Also Windows playback devices shows 6 devices for HDMI sound, all disconnected AND iirc Linux also had multiple sound devices(with catalyst not open-source radeon/ati), but let's ignore that for now maybe 
Everything worked fine before I reinstalled Windows not too long ago, I remember having multiple sound devices then too but not the display ones too. I haven't yet seen any harm from this but I am debugging problems with a game with it's developers and want to rule driver issues out and fix this kind of problem. So, is this a common problem or am I the first one? Here follows info about my system.
MSI AMD Radeon HD 7750 R7750-PMD1GD5/OC
Catalyst driver 12.10, had 12.11 beta for some time but uninstalled and reinstalled 12.10.
Windows 7 64-bit Ultimate with SP1
ASUS Monitor via DVI, (Samsung HDTV via HDMI, not in use currently but could have been plugged in while initial install commenced)