The 83SE had a similar issue at one point, not retaining certain settings and it almost sounds like what is happening for you. What they told me was to clear the on-board cache, do a factory reset (will not affect the firmware) and then go ahead use it again, though everything should be default at that point and you will have to redo any settings you had. If it is not retained, it is possibly a flaw in the firmware you are running.