timeout error while flashing firmware arduino mega 2560

can anyone give me an easy sollution??
i'm not a programmer or anything close to it, so if there is an easy way to fix it that would be great!!
this is the error message I get everytime I try to upload the firmware:

Sketch uses 52,834 bytes (20%) of program storage space. Maximum is 253,952 bytes.
Global variables use 3,028 bytes (36%) of dynamic memory, leaving 5,164 bytes for local variables. Maximum is 8,192 bytes.
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

Does your sketch contain a string with 3 exclamation points in a row in it? That caused an old version of the bootloader to choke (it put it into some diagnostic mode), and that bootloader is still used on some clones currently shipping.