P67 SLI Micro with I3-2120 running Win7 ultimate x64, system assembled 1st week in July.  Ran OK up until last weekend, then started getting usb device not recognized messages as system was running.  KB and mouse intermittently disabled - they were connected to usb 2 ports on backplane.  Also the magicjack connected to front port kept going and coming back.  Finally moved the KB and mouse to front ports whicha appeared to resolve the problem.  Last night heard the usb ports activating and deactivating again then found no KB and mouse again.  Apparently now have no working usb ports.  Machine is working fine except for that I am connected to it via rdp and this way have a full kb and mouse control.
This is not a driver problem as I have no kb in bios setup either anymore, luckily have an old ps2 wired kb that I can connect to the ps2 port but that doesn't help the mouse issue.
Basically at this point the machine is not really functional so I assume I will request an RMA
Wondering if anybody has any other suggestion as to any other method of proceeding as sending it back for replacement is a PIA and means that in the interim I will need to get another mobo to be able to keep running.

What is plugged into you USB headers? Your BIOS up to date?

They are known for problems with USB3 but not the other USB ports. Did you reconfirm all settings in bios are correct especially the usb section (are all devices enabled)?

Reset the cmos and restarted.  Made the ncessary changes in the bios to get raid disks started and still have the same issue.
The USB headers are connected to a multiple slot card and front panel usb slots that are not working.  Bios v 672 1.18 x64 build date 07/01/2011 14.36.31, probably not the latest however the system worked for several weeks prior to the ports disabling.
Have now discovered that not all the USB ports are defunct.  Actually appears to be just the 2.0 ones.  Have got the keyboard and mouse working again by connecting a dell multimedia kb to to a usb 3 port and connecting the mouse to an extender port on the kb.
To me it still sounds like a defective board.  I'll go and check what the latest bios is for the board  and what issues it says have been resolved.
I did see other posts on the forums here regarding usb port issues with mother boards that had usb 3 support on them.
 
I see 3 bios flashes for this mobo, a119, a120 and a121.  None of them appear to use the same numbering that I see in my bios when I change setting, where dod I actually find the bios number?
Are those 3 flash packages cumulative?  I see nothinguntoward in them and wanted to know if I should apply all 3 in sequence or just the latest one?

Latest one.