"not in sync" after successfully burning UNO bootloader to a duemilanove

Now I re-bootloaded the duemilanove and was able to load blink without delay. Now it's stuck with this sketch and won't load other code:

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

:((