"Not in sync" and "Protocol Error" Help

Whenever I try to upload any problem, I keep recieving a "not in sync" error and a "protocol error". Eep, what do these even mean and how can I avoid them?
I've checked com ports and boards and connections and all that classic stuff but this just won't go away
Thanks in advance


Have you tried the search box in the upper right corner of the page?


See: http://www.arduino.cc/en/Guide/Troubleshooting for some suggestions, as well as information you can provide to make it easier for us to help you figure out what's going on.