[LAU] strange behaviour with novation launchpad

Hi I'm trying to use my novation launchpad with chuck. It seems to be plug/play, at least I didn't do anything except plug and play :-) However it's acting a bit strange in one regard. The first time I handle (read presses from the launchpad and sends something back to turn lights on/off) it works as expected. However the next time I launch my chuck code (without turning off = unplugging the launchpad) it doesn't send presses. However the arrow up, down, left and right buttons (or at least the up-one, that's what I got used to use) works and after pressing it the other buttons start sending again. Every once in a while, it's the other way around, I have to press a grid button before the arrow pads start sending. I checked my chuck code quite thoroughly, and played with various things to remedy the problem, but still it might be something I send that messes up the launchpad. Can anyone recognize this behavior? Or the opposite: testify that it works without this quirk? Any ideas how to approach the problem, narrow down the possibilities and hopefully eventually find a fix? NB: I'm running arch linux with kernel 3.0-rt... -- Atte http://atte.dk http://modlys.dk