I've owned an Ernie Ball StingRay for about 5 months, love the bass, but I'm having one annoying problem. The pickup seems to keep backing out of the body. It's to the point now that after a show, the pickup poles are almost touching the strings, as a result, the poles are getting pretty beat up. The strange thing is, all three pickup screws seem to be slipping pretty equally. Is this a common problem on these basses? And if so, are there any easy fixes? I'm getting sick of having to re-adjust my pickup height after every show! Any help would be appreciated.