I have an ESP V-500 that ive had for about a year and a half, and Ive been having continuous issues with it. For a while, what would happen is spuratically when I toggle the pickup switch selector sometimes the signal will just cut out completely, and ill have to keep switching it until it comes back on. I looked inside where it had the wiring and I couldnt find any problems, I looked at the jack and didnt see anything (mind you im not a pro at these things so i can be missing something), its never the battery, because when I change it it still happens. The thing is is that I brought this to my local guitar store and niether me nor the guy that works there could see anything wrong with it . And whats REALLY wierd is when I tried it on all the amps at his store it never did it there (like I said, spuratically). But when I play on my amp or a friends amp it still does it. And lately all of a sudden my volume nob cuts the signal out sometimes too when I turn it (I was told it was the switch inside was bad). I cant figure out whats wrong with my guitar! Any advice?
You should take it to your local guitar shop, see if they can find out what is wrong with it ;D
probably something wrong with the toggle switch's circuit board.

take it to a tech. he'll have the entire circuit rewired for you and that should eradicate your problem.
just get new pots and a switch?
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If the tech at the guitar store has checked the wiring and is convinced there's nothing wrong, and the problem only happens through one amp, logically it must be the amp (or another part of your rig like cables etc) at fault.

I can't think of any circumstance where pickups would affect an amp in this way, but perhaps somehow the preamp/input circuit can't handle active pickps. Maybe even a grounding issue.
i would say have the tech replace the switch, its not too costy, and in the process he'll have to re-wire alot of it which should fix the problem if its not the switch itself.