MultiWii Pro - Error Uploading

Hello, I´ve the same problem: I bought the MultiWii Pro flightControler w/MTK GPS,(use arduino 1.0.5) and every time that I try to upload the firmware to the Multiwii, appears:

avrdude: stk500v2_ReceiveMessage():timeout avrdude: stk500v2_ReceiveMessage():timeout avrdude: stk500v2_ReceiveMessage():timeout avrdude: stk500v2_ReceiveMessage():timeout avrdude: stk500v2_getsync(): timeout communicating with programer.

I´ve used MultiWii_2_1_mega2_0_gps and MultiWii_MEGA1_gps I push the reset button when I update the firmware, but still the problem, I used other laptop and the same problem... Anyone knows any solution, I´ve read about this in Arduino, but it´s complicate for me. Thanks...