Arduino Duemilanove won't upload

My arduino board won't upload anymore. I keep getting the following errors:

avrdude: stk500_getsync(): not in sync: resp=0x30 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

any suggestions?

I have tried everything. Making sure the board is selected for Atmega328, making sure it is on the right port, and it still won't upload and gives me the same errors as before.

Please Help?

Did you try the troubleshooting guide? http://www.arduino.cc/en/Guide/Troubleshooting#upload

Hi guys! I have exactly the same problem. Arduino Duemilanove won't upload. These are the responses:

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

Resolved! See this: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1237844360