2003 ford focus radio

I would suspect either a bad fuse in the radio or the radio LCD itself is starting to go out.  You will likely have to take this to a Ford dealer to have diagnosed.

I would depend on when it does it.  It could be nothing serious, but you might be better off getting an aftermarket stereo.  The reason for that is because these factory radios actually have a stupid anti-theft feature other than the removable face plate.  You see by disconnecting the battery, you render the unit inopperable until special security codes can be put in by the dealership, you're allowed 10 chances every 30 minutes, after that the unit is completely useless until it can be reprogrammed by the dealership (expensive).  Just get a new one from Best Buy or something.