Here's a theory I have (and I admit I'm no good at electronic ever since plugging my ErectorSet motor into the wall outlet and waking up sometime later...)

I was having a bad ground connection from the empeg to the battery (either at the battery, the dock or a connection) so the empeg grounded itself along the RCA's. Once I pulled the RCA's and restarted the player, it was forced to use its "dodgey" ground to the battery. Once this ground was being used, re-connecting the RCA's had no effect. Does this makes sense? Will a device change where it's getting its ground from?

Off to do more testing.