USB2 working as USB1.1

Hi,
I am running a via chipset which was working fine on Vista. I have now installed windows 7 and all of my front connected and motherboard mounted USB 2 ports are now working as USB 1 (seriously making my iPhone syncing life a misery).
If needed I will post my motherboard etc when at home, as can't remember off top of head.
I have tried flashing BIOS and installing drivers for chipset (those which would work on 7 anyway) but Via USB seem to be coming through windows update since XP, so not much joy there as nothing on 7 WU.

Any Ideas, as I thought there would be more about this issue out there?
Many Thanks in Advance
Peter

Do you rear ports still work as USB2? If you can post your motherboard name I'll see if I can find any further info on this for you