I think this is a common problem. Hugo mentioned to me that communication between the player software and the display PIC is 1-wire serial with software timing (i.e. asynchronous), and sometimes the data get slightly out of time during sending. I wonder if instruction cache issues affect the timing loop?

I don't think the player ought to be sending any dimmer commands in home mode, but I do sometimes see reduced brightness after boot-up, so I guess it does.