Dual Strike v3. Problems with MAME keyboard default

[da...@basiccomic.com]

Hi

I just installed two Dual Strike v3s in my arcade cab (replacing two MC Cthulhus), mainly for their ability to act as MAME keyboards.  My cab PC is running Win 8.1.

I set both boards up via the config editor (after initially getting the 'not recognised' error - so I figured out the HK on plugin fix).  My setup is pretty standard except for the following:

I don't want the boards to be recognised as PC controllers but rather MAME keyboards.  So I set them up, saved the config to the boards and fired up MAME - all worked well.

However, on reboot I get the old USB error - not recognised - again.  I've tried:-

1) Having 'PC controller' off and default mode to autoselect. (ideally, this would suit me best as I also want to use these boards on a PS3)

2) Having 'PC controller' on and default mode to 'MAME'

Neither work on reboot.  I get USB error code 43 every time.

I've updated the firmware but that didn't seem to help.  Would it matter that my PCs USB ports are always on (even on standby - and there's no way to turn them off)?

I'm completely baffled now.  Any help would be hugely appreciated.

[da...@basiccomic.com]

Update:

Neither of these boards works at boot, but when I unplug them and reconnect, they're fine.  What could be causing that?

I've also tried them out on another PC (a laptop) and they work fine whatever I do.  The difference with the laptop is that the USB ports shut down when the PC does.  Could this make that much of a difference?