Let's try this. Use the USB ports on the rear and the ones supplied by the motherboard. Those front ports and on USB cards could lead to aggravations.
I'm having an issue with couple of external USB ports which are connected to my system. Because I have my mouse and keyboard connected to an external USB port somehow I loose the connection and I can't use the mouse or keyboard, actually I need to turn off the system in order to have both USB ports back on line. I wonder if this is an issue with my system or a Windows 7 issue.
I'm running Windows 7 Ultimate with Intel Core 2 Quad Q6000@ 2400GHz 2.40 GHz
RAM: 4.00 GB (3.25GB usable) 32-bit Operating System.
I never had this issue before under Vista or XP as this system was running on both OS.