Erik,
I have the same experience. I was getting audio drop outs during playback, so I experimented a little.
In my Mac system preferences I set the audio out to “Headphones (Headphone port)”.
Went back to PPro CS 5.5 (using the AJA settings) and played the timeline and no more audio drops outs! Not sure why this is, but I do agree with you that the AJA drivers are buggy and not as good as the ones for FCP7.
For example, when I scrub the timeline not using the KONA 3, it scrubs smoothly and the timeline is very snappy and responsive. When I use the KONA 3 board, it seems to slow down the timeline, and when I scrub the timeline it just skips to frames and does not give me smooth playback. This is problematic when trying to do fine cuts.
Miro