Petherf,
Are you using a powered USB port (either part of or external to the PC), or an USB hub that isnt powered?
Sometimes unpowered USB hubs dont work well with joysticks and TrackIRs. If unpowered USB, try a powered one.
If powered USB and the problem persists, what happens if you try it on another PC, same thing?
This would help eliminate if the problem is systemic (follows the WH) or particular to a specific PC's configuration.
Else, just wait on Trust-Master to see what they come up with if alot of folks are seeing it too.