i do have the same problem somehow. i was jamming half way thru and out of sudden, nothing came out from the amp. i tried plugging the jack in/out, connect/disconnect my pedals until everything went back to normal. at 1st, i thot it was the studio's amp. but it happened again on the other jamming session in another studio.
until now, i still can't locate the fault, dunno it's the prob with my guitar or my pedals.
still waiting for the intermittent fault to become permanant, before i could troubleshoot.