I've noticed some odd behavior as of late on my left nub, very similar behavior, but not entirely sure if it's the same... I notice it more with N64 emulation, on the XFCE desktop the cursor seems to go slower when moving in some directions. For some reason powering down and back up temporarily fixes the issue, but will return after a short while. I haven't noticed this issue on my first batch Pandora, just my rebirth.. It could be hardware related, but I swear I didn't have this issue until I updated to the newest Super Zaxxon.. it may just be coincidental though.. I need to do more testing and I haven't done a real good test on my first batch Pandora..