Comment 3 for bug 1041684

I'll give that a go, but I believe that is for switching to usb 1.1 which isn't ideal. I've tried the arch distro as well and it has the same problems. I'm guessing this is a issue with the synopsis driver. Out of interest if anyone has a usb sniffer can you check the polling rate of the keyboard.
It makes little sense that this is happening though as presumably the cpu is easily fast enough to manage ~125Hz scan rates, even if the cpu was too slow to scan in the new value, it wouldn't stick on continuously. This would suggest that the HID driver is not being called often enough or is doing something wrong, but I'm guessing it would be called when the usb poll rescans the keyboard. The HID driver functions perfectly on everything else anyway.
I checked the synopsis driver for something stupid like a missing volatile declaration but it's there. I'm not great at trawling through makefiles unfortunately, might be worth checking the compile flags and verifying that volatile statements aren't being ignored