Arduino upload error

Hi, I've been having problems uploading to my arduino Nano v2.
This error arose after using Serial.read() to read bluetooth data. After reading through all the threads about this problem it seems to occur after using serial. I should also mention I've tried this from multiple computers and get the same error. I had the same problem on my Duemilanove but managed to resolve it, no luck on the Nano though.
I get this error:

avrdude: stk500_getsync(): not in sync: resp=0x30
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I've read through all the other threads about this problem with no avail. I've got all the latest drivers, correct board set, correct COM port.

Any ideas?

Hardware info:
Win Vista
Arduino Nano V2

Cheers Rowan.

Get a real AVR programmer.