Hello Mike!
I think you should consider what I found out about my left mouse button problem. Maybe it would help your RMB dilemma also?
http://www.amiga.org/forums/showthread.php?t=66445Read my last post in this thread please.

Also I noticed you have some odd colored pins on cia chip (U7) nearby keyboard connector, this CIA will affect joy ports. Something had been done to it?