Same problem here with multiple jobs i have done.

We had just finished servicing all RFX extenders and remotes with the 'LOCKING UP' firmware, when a customer whos remote we just updated.

i think my speakers are blown up he said. The remote just locked and the volume kept going up! with the message in the screen 'system in use by other user' . Only he has just one remote!! . 

i went to have a listen, and they were blown up.
The bigist problem was that he has amina inwall speakers! so the speakers had to be hacked out of the concrete walls and his wall has to be replasterd!! 

he was not happy..   

Philips said they could not help us with this. so we had to pay for the replastering and the new speakers!