I have an issue that has just started occuring with my MX518 Logitech mouse. I bought a Razer Copperhead over a year ago. Played UT2004 with it for a very long time, worked very well. Then one day started having this usb disconnect/reconnect plug and play sound, whilst the mouse froze up. I figured it was the mouse dying, so I bought an MX518, and the problem went away. It's now been 4 months since then, and the problem has reoccured. I'm using an Enermax Coolergiant EG485P-VHB 480W PSU w/ AnyoDenki fan blower, so that shouldnt be the cause. I've also purchased an external AC powered USB Hub that can power max 500 mA to each port, and hooking up the mouse to that does not resolve the issue, which is disonnect / reconnect every 5-10 seconds from the usb. This problem only occurs during UT2004 and not while using Windows. Any possible solutions that you guys may know of or suggest, PLEASE let me know before I go about replacing parts, one by one.

Two things come to mind. First, check the IRQ assignments for the Graphics and USB controllers to see if there is sharing. Second, try moving the mouse to a different USB port. Using a powered hub is better than using a passive hub but you are still only able to utilize the assigned percentage of bandwidth for that controller. USB controllers usually support 2 ports each. That means sharing. I suspect the problem you have is that when gaming the graphics are using more resources than when just performing normal tasks. Depending on your BIOS settings you may have an option to assign an IRQ to your graphics (AGP?) in the BIOS settings. Doing this assures that IRQ won't be shared with other hardware. Also be sure that PnP OS is Enabled in the BIOS. Each time hardware is added to your system Windows or the BIOS MAY change resource allocations to suit the new configuration. One last thing to consider. There are only so many CPU cycles to go around. Additional programs running in the background use cycles. Check for spyware/ malware and clean from your system. If you don't already use them, try AdawareSE and Spybot Search& Destroy. Find them both here: http://www.pcworld.com/downloads/