I am have a very, very, very hard time with RMB on a powerbook g4 A1138. It will work sometimes, but most of the time I just give up. When it does work I have to do the two finger touch 20-30 time, I am not kidding I've counted. Just to get it to work once. For the last hour I have not been able to get it to work at all.

touchpad or actual mouse?

if touchpad use two fingers at the same time. it likes it. then you'll get the rmb.

I learned to use two other fingers rather then the two I was using. So, this is much better.

Thanks :)

You could also check the Touchpad settings, if you haven't already done that.