Thanks for your reply - have only been using Sustain pedal and problem still there when remove it.

Yesterday was able to play a whole piece, and for a while I foolishly thought the problem had gone away. But I accidentally left it plugged in overnight (the first time ever) and the R2 had gone peculiar when I tried it in the morning. The R1 was still OK, so I left the keyboard on for a while longer and when I came back, sure enough R1 had also gone dull. Affects R1 or R2, whichever I'm playing on - or in this case, not actually playing on.

I'm wondering if it's something to do with heat and circuit boards.

Ah! have just read Serge's info on the Expansion cards/version numbers. Thanks for clearing that up Serge.

So you're sure the keyboard's pointer to the flash memory location will not be affected when I initialise?