Waldorf Microwave Button issue

I have recently acquired a Waldorf Microwave revision A. It had sat unused for a few years and the battery was dead. I fitted a new battery and OS 2.0 software EPROMs. I loaded the factory programs via a SysEx dumo, and all the patches are playing fine. However, the four program editing buttons are not behaving properly. When I run the button test in Diagnostic mode, button 3 is reading as button 2. So, to be clear, buttons 2 and 3 both read as button 2. All the other diagnostic checks were ok.
Has anyone ever come across this problem?