Newbie Question - Can't upload second time

Hi -
Newbie question, thanks for your help - I was able to upload once to my new Duemelanove, but since then just get the following error. I'm running Windows Vista, Atmega 328:

Binary sketch size: 2672 bytes (of a 30720 byte maximum)
C:\Users\Chris\Desktop\arduino-0018\hardware/tools/avr/bin/avrdude -CC:\Users\Chris\Desktop\arduino-0018\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega328p -cstk500v1 -P\.\COM3 -b57600 -D -Uflash:w:C:\Users\Chris\AppData\Local\Temp\build267836952589309790.tmp\sketch_sep01a.cpp.hex:i

avrdude: Version 5.4-arduino, compiled on Oct 11 2007 at 19:12:32
Copyright (c) 2000-2005 Brian Dean,

System wide configuration file is "C:\Users\Chris\Desktop\arduino-0018\hardware/tools/avr/etc/avrdude.conf"

Using Port : \.\COM3
Using Programmer : stk500v1
Overriding Baud Rate : 57600
avrdude: ser_open(): setting dtr
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Recv:
avrdude: stk500_getsync(): not in sync: resp=0x30
avrdude: Send: Q [51] [20]
avrdude: Recv:
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

avrdude done. Thank you.

Hi, just a few ideas...

What has changed since the time it worked?

If its a different board it will have a different serial port name in the list if you are on Mac or Linux.

Are the drivers for the USB definitely installed? Perhaps try reinstalling the driver?

Do you have another board that you can try, in case you have fried it?

Does the power LED light ok?