Usb not recognized (flash drives and externals only)

I have done a few days worth of research and have tried multiple fixes and still cannot connect any flash drive or external drive to any usb port on my computer without the dreaded "Usb not recognized" error. My mouse and keyboard are both usb and have worked fine though.

I have unplugged the power cord from my psu for a few minutes. I have booted into safe mode. I have deleted the infcache.1 file. I have check my Bios settings (and have latest bios update). I have completely removed all the usb devices in device manager and rebooted which reinstalled everything. I have booted the computer up with a flash drive already in a usb port. I have gone into Drive Manager to see if anything is recognized without a drive letter. I have even applied the hotfix from here - http://support.microsoft.com/kb/976972. Nothing seems to work, yet all of these devices work fine on my netbook running Windows XP.

When I originally installed Windows 7 everything was working fine. I would say it roughly stopped working a month or two ago. I don't constantly use flash drives or my externals so I could be a little off on the timeframe (why I didn't do a system restore). I first noticed the problem when I plugged in my Tmobile G1 phone to transfer files and it wasn't recognized. My phone would still charge off of the usb port, but I couldn't mount and browse the 4 gig sd card in my phone. It was working before because I have files on my phone that I transferred from my computer after the Windows 7 install. I started testing out my known, working flash drives as well as my usb powered 2.5" external drive and they too come up unrecognized on all usb ports (front and back).

My specs:
AMD X2 5000+ BE
Gigabyte GA-M55plus-S3G mobo
G.Skill PI Black 4GB ram (2x2 - DDR2 800)
2 Western Digital Sata drives
Nvidia 9800 GTX+ video card
450 Watt PSU (don't remember brand right now, but good amp rating on 12v for video card).
Windows 7 Ultimate x64

The only drivers I am using for the system that are not the default W7 drivers are for my video card and onboard audio. Onboard audio is the only W7 driver provided on the Gigabyte website for my motherboard.

So, anybody know anything I can do, check or double check or should I start considering formatting and a reinstall of W7 (which I have been trying to avoid)?

I would like to add a twist to this question. I use Windows 7 Pro. I have several flash drives that I keep certain files on, the largest one is 16GB, the others run 1G to 6 G. I am part of a home network with several computers on the network, they are all wired not wireless. When I am the only one turned on and using the computer and plug in the 16GB flash drive it does not show up as a second drive it is read by clicking on the first computer shown as one of the computers on the network. All of the other drives show up as removable mass storage, the larger one takes on the name of that first computer on the network. This not a big problem just does not seeam right.

Have 4 usb flash drives/ jumpdrives what ever you like to call them, all used to work up until approx mid Dec 2010.
2 x EagleTec aren't reconised, but 2 x Lexar are reconised.
Tried all in every USB port on desktop but still the same.
Very strange. (Windows 7, Home Premium, AMD Athlon II x 2)

Try changing the USB cable! I had the exact same problem on my phone and a printer. A cable change solved both problems.