I recently used registry mechanic 7.0 to clen up my registry. when i restarted my computer many programs stopped working, including the damned registry cleaner. all because 1 file called 'msvbvm60.dll' is missing or something. i tried to restore my comp using system restore but it wont restore it to a point before the cleanup was made.
actually ccleaner has a registry cleaner and everybody complains about that also, but I have no problems with it.
I think when it comes to registry unless you know what you are doing you should not mess with it, I dont' know any registry software that is full proof not ot make mistakes but next time you clean registry don't check all the options, choose to delete dead keys only.