My recently aquired Rio-car was exhibiting this same kind of behavior, I contacted support. The player seemed fine when v1.03 was on it except it would never keep time when unplugged, I could reinstall 2.0b7 only after reinstalling 1.03 first, if I tried reinstalling 2.0b7 first it would freeze during boot at 'starting audio'. When I did get a successful 2.0b7 install it would run OK (clock still wouldn't keep time) until pressing 'source' button on remote that would freeze it up again.
The problem turned out to be a chip like the other thread you mentioned in your post. Contact repair guys and get it running, it took mine just a week round trip to get back to me & they paid for the trip. Hope you find out what it is and can use it as it was intended, I was fortunate that I had my old empeg to use while the new one was at the hospital.