The left and right arrow keys are not working except when used with a modifier key like shift or command. The up and down arrow keys are fine. I don't know if I pressed some key combination that made them unusable but if anyone knows how I can fix this please let me know.
I am also experiencing this problem & I also don't have Hyperspaces installed, so as I have read your post and am certain you have a considerable breadth of knowledge regarding PowerBooks, the originally posted problem remains for some of us. My trackpad had gone dead for a couple days before the right & left arrow keys stopped working. My up & down keys are fine. I can't find a cause or solution, either.
Oh, and I have been running Apple computers since I bought my first, a IIc in 1984 so I, too have some experience with Apple computers. But, maybe we could just keep it to the discussion of the problems & their solutions since that's the point of the forum, right?
BBen: With your depth of knowledge and your sharp focus on the problem, no doubt you've already tried logging into a different account to see whether the problem also exists there or is limited to your own account. How did that turn out for you? If the problem persists across different accounts, that suggests that it may be a hardware fault. If it doesn't, that points toward a possible software problem in your own account: perhaps a corrupt preference or an incompatible bit of software.
And BTW, I appreciate that you didn't use your first post in these forums to call anyone "ignorant". Insults really aren't encouraged here, and I don't like them any better than anyone else does.
I have been experiencing this issue as well. Although I have not figured out the reason for my issue (i do not use Hyperspaces) I have found a solution to the problem. Simply go into [System preferences] > [keyboard] > [keyboard shortcuts]. Click the plus sign to add shortcut, select itunes as the application, and add Next and Previous as shortcuts with the key (right)(->) and (left)(<-) respectively.
I had the same problem but it wasn't HyperSpaces that was the problem but "I Love Stars" that automatically took over using the left and right arrow keys. Disabled the arrow keys in "I Love Stars" and it fixed the problem.