Error: avrdude: stk500_getsync(): not in sync: resp=0x00

hi everyone,

I have an Arduino Dumilanove, Atmega 328 and a code for an actuator. When I'm trying to upload the program, the only trouble I have is that the error: avrdude: stk500_getsync(): not in sync: resp=0x00 keeps showing,, I've checked for the COM port, and tried to press the reset button while it's compiling and stop pressing it when it's about to upload it, but nothing works. It also gets really warm, so I even tried with another Arduino Duemilanove and the same error came up.

If any of you could give me a hand, i would really appreciate it!