USB troubles

I'm having trouble with some of my USB devices. I have Win XP Sp2 and all hotfixes installed. I have a powered USB hub plugged into the rear USB port on my Mobo (Biostar P4m80). If I plug my Canon printer into the hub, it is recognized. If I plug a USB flash drive into either the hub or a port on the mobo, it is not recognized. If I plug a gamepad into either the hub or the rear port, Windows says it has detected the device, but then it fails to load the drivers. However, my USB mouse works when plugged into the mobo USB port! I recently installed a 8-in-1 USB panel that plugs directly into a USB header on the mobo, thinking that would circumvent any of these troubles. However, this device doesn't work either. The red lights on the front are on, but if I plug a flash drive or a Compact Flash card into it, nothing happens. Since I installed this reader, everytime I start the PC, Windows wants to "install" both of my CD-RW's, and a "mass storage device". But if I run the installation, it fails to find the drivers. However, the CD drives seems to work OK. In my system devices, there is only an exclamation point in front of mass storage device in "Other USB". In BIOS, I enabled USB support for "mice, keyboards, and storage devices". I'm at a loss to figure this out. Would re-installing Windows work, or is that a final resort?