> >>>> (Entertainingly this is true for Dell GX280 BIOS revisions A04  and
> >>>> the lastest A06 which allegedly fixes USB troubles. A05 seems to
> >>>> work.) How can I help?

I've also got a bunch of GX280's  that are sitting with BIOS revision A03 
because if I put a latter one in the keyboard stops working (hadn't tried 
A05).  These machines also don't see at all various USB devices that work 
quite happily with the previous generation machine, the GX270 (as reported 
here some time ago).
I also note that the next generation machine, the GX620, also doesn't see the 
keyboard once you get past the boot loader and there is no earlier BIOS 
revision I can try with that machine.  I haven't yet tried commenting out 
ehci for it to see if that makes a difference.

I'm keen to get the USB issues with these machines sorted so will help in any 
way I can but someone will have to point me at anything useful I can do.

cheers
mark