thanks for your post.

To quote the setup wizard:

To perform the requested operation, Remote Buddy will try to unload 
it and replace it with the version shipping with this release.

This requires that there are no references the kernel extension from 
running application. Please quit all applications that have support 
for the Apple® Remote (except Remote Buddy of course).

If loading the new version of the kernel extension fails, a reboot 
will solve the problem. <<

So, installation did almost certainly succeed, but loading didn't. A 
reboot will solve the problem.

Best regards, 
Felix