Could be one of many things, I've had the problems of picking up cable TV sound on my scanner in apartment complexes as well, it shouldn't happen but it does. The only real solution I've found for that problem is moving your scanner (and more importantly antenna) to a different location. If you can't hear either the fire or sheriff repeaters it is probably due to poor location. Can you hear the sheriff's repeater when you're outside your complex? Are you using the scanner's stock antenna or some sort of other antenna setup?
I'm not that familiar with King George's system, but the DB page for it says the sheriff repeater (159.0900) can be encrypted. If this is the case, maybe King George is running DVP?
Hopefully somebody who lives closer to this area can shed some light on your issue.