I had a similar issue. I had to reinstall the OS and the drivers. This fixed the issue at first but now the pen functionnality is lost when ever I am running on battery power.
Running off outlet, fine.
Running off battery, fail.
I tried resetting the PRAM and SMC, tried running the battery all the way down, even through the reserves, tried using a friends macbook battery, no change.
I zeroed out the drive (single pass) and re-reinstalled, no change.
Every so often it will decide to function correctly but stop after a few days.
Anyone have a similar issue? I emailed OWC and they don't know what is up. The Axiotron forums have no answer either. A local fix it shop is trying right now, but they are not hopeful at all.
Is my hard drive just totally iced? Is it maybe my I/O port? Is it the screen?
I am using OSX Snow Leopard with the non NVidia graphics chip.
Any help would be greatly appreciated.