The reason I brought up the QT libraries is because of the error message. Whenever you get a "feature already defined" or "previously declared" types of errors, it usually indicates there are two files containing the same information. That can confuse whatever program is running.
Unfortunately, I'm not very knowledgable on library configuration. You may try running 'ldconfig' to update your shared library configuration. If that doesn't work, then I'm not sure where else to look.
I hate to see someone have to reinstall, but sometimes it's the easiest way to get back to a good state.