not in sync/protocol error

I get the error:
avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I just got my Arduino Duemilanove ATMEGA 328 today and it was working just a few minutes ago (well I sometimes takes a few tries to upload the program). I selected the right board and serial port, I am running Vista 64bit.

Figured it out, had to disconnect everything.

Just wondering what would cause me to have to do this.

Edit: Also I have to unplug and replug the usb in to get it to work after i disconnect everything

I get this error constantly, and i cant upload any sketches

Read this
http://www.arduino.cc/en/Guide/Troubleshooting
thats how i figured out how to fix mine.