Yes, that is the motherboard. The OS is Windows 7 Pro 64-Bit. I saw some of the links on the logitech site, but none of them really helped. The keyboard and mouse are fine on two other computers on my desk and even the mouse is fine on the GA mobo PC; it is just the keyboard that becomes sluggish on the GA mobo PC.
I'll keep looking around. I don't really have the time to do a bunch of incremental testing to try to identify exactly what is causing the problem. The only USB setting I think I saw in the BIOS was to enable "legacy mode" which seemed to make no difference.
I'm not sure the GA mobo is the problem, but I just wondered if someone here had seemed something similar. I wasn't coming up with much from Google of others having a similar enough problem. For some the mouse was sluggish which is not my issue, and for others it was a wired keyboard that was unresponsive. I think I have a wired usb keyboard somewhere I can probably try without too much hassle, but my assumption is that will work. I don't have a keyboard with the old-style ps/2 connector to try.
Thanks,
David