I had been having this problem on both a 20" imac G5, and my 17" powerbook 1Ghz. It was driving me nuts. My default keyboard layout is 'Canadian' (using tiger), since I AM actually in Canada.
Changing my default layout to US fixed the problem.
I find this particular bug
extremely irritating, given the cost of this software.
Thank you, however, for the note -- at least I can use shortcuts now.
Cheers
T