Last night, I was replacing strings on my bass. I used some heavies and had some problems with some of the tuning machines. They felt like they might have been stripped, that is, they would tighten to a certain point and then "slip" back. Me, being a genius, decided I would use a flat-head screw driver to help the tuning machines as I tightened them, as the strings were still rather floppy at this point. Basically, what I did was as I tightened the string I kept turning the screw driver in step and this seemed to combat the slippage. As I was putting on the E string, all of sudden the other strings went slack and I looked at my bridge it had been pulled out, stripping the screw holes. A few questions: 1. I'm assuming this was caused by me over-tightening the strings. Is this the case? I've never changed strings on a bass before so I guess I did something wrong. 2. If I didn't cause it, should I return it to get replaced? 3. Is this something I can fix myself?