Problem with my Les Paul

I have a very nice 2008 Gibson Les Paul, it is like standard, but with faded thin varnish. It was kind of out of action for a while as I love my Tele. But in the past few weeks I've been playing it a lot more and it is sounding great. But yesterday during a gig it acted up a bit. Basically what happened, while I was playing a lead, it sounded like the pick up output went down... Not a big problem as I just swapped back to the Tele. But I had a look of it today, and all the wiring looks fine, and if i push the bridge pick up from side to side, it comes back to life... The pickups on it are the Gibson burstbucker zeebras. Any one ever come across anything like this before?

J.P.
www.jpkallio.com