I've seen a number of posts regarding the following error so I wanted to share my solution.
When I tried to upload my sketches, I got this error:
"avrdude: ser_send(): write error: sorry no info avail"
My Arduino Uno was connected to a Belkin USB hub. It showed up as COM22 under the Windows XP Hardware Manager. I simply removed the USB cable from the hub and connected it directly to a port on the motherboard. Voila. Sketch upload successful.
Hope this is of some small help to another frustrated Arduinoid out there.