I understand that your mouse freezes or stops responding and you believe that this may be related to a BIOS bug.
In regards to the problem that you are experiencing, we have not received any reports of issues similar to yours or problems with the USB ports 2.0.
How did you determined that the problem is indeed related to the mouse as I believe that this may be the whole system freezing. Have you tried testing the motherboard out of the chassis to check for shorts or grounding?
Have you rolled out the operating system being the cause of the issue?
Please check if your RAM memory is 1333MHz at 1.5v, you may be having background problems that are giving you these freezes.
My past Intel motherboards have been rock solid until this experience.
You mentioned this one has been as well up until a couple of months ago when the problem started so I don't think there's an inherent problem with the board itself (otherwise this forum would be flooded with similar posts from all the other users with this model of board). When you performed the fresh install, at what stage did the problem come back (after installing what software/drivers and in what order)? Tell us a little about how you performed this fresh install. Have you tried plugging the mouse into a different USB 2.0 port? I'd certainly be hanging onto the old keyboard and mouse because chances are there's nothing wrong with them (you could plug them into another PC to test them out).
I am running this board with a 2700k, and I am disappointed. Both my mouse and keyboard are intermittently not working as well. I update the board's firmware to the latest version and the problems went away for a solid week and a half. Now, the problems are creeping back up again.
There are plenty of people having issues with the USB 3 ports on this board also, found through googling the board's model number.
Anyone find a solution for this as of yet? I find myself unplugging my keyboard and mouse MANY times until the board "catches" them. Sometimes I have to restart my PC upwards of 10 times before the USB ports act stable.
This is pretty unfortunate and upsetting, because I spent the money on this setup in order to have the "most capable" experience, as coined by Intel. That's also why I bought a board made by them, to ensure I was providing the processor exactly what Intel recommends.