Preamp problems in Stingray 5 HH

Hello everyone, I have a 2008 Stingray 5 HH that I purchased in the spring of 2009 and the preamp seems to have gone bad. There is a lot of hiss occasional squeals and sometime very thin weak tone, the interesting thing is when I experience these problem I pull the jack out and put it back in and it sometimes makes it better, sometime not. I’ve replaced the battery and have tried different cables into two different amps, same results.

I sent an email to customer service last night and am waiting on a response. Just wondering what I can expect, will I need to take my bass to an authorized dealer? Will they send me a new preamp and leave it up to be to replace it or have it replaced? How much will the new preamp cost?

Anybody go through this with Ernie Ball/Musicman before?

Any info will be appreciated. Thanks!