One more possible error source that springs to mind would be that you 
have mapped the respective buttons globally, so they no longer get 
passed through to the respectively active Behaviour. Do these buttons 
work ok for you in i.e. iTunes?

Beyond that, I fear there's little I can do. Remote Buddy uses 
AppleScript to tell Keynote what it is supposed to do - and doesn't 
have any influence of what Keynote does beyond that point.

I only have the latest version of Keynote available to look at and 
test with. It may be possible that older versions did not implement 
the required commands - although I'd doubt that since those really 
are the most basic ones.

Best regards, 
Felix