Protocol error first time downloading sketch on XP

I've just received my Arduino USB, have installed the drivers, IDE v10, and rebooted.

I'm running Windows XP, SP2, IDE V10, with FTDI drivers 2.02.4.

Device manager sees the Arduino (USB Serial Converter), the Arduino Green power LED come son when I plug in the USB cable, but the Yellow LED is flashing. This looks like an error code, but I didn't find any references to erro codes yet.

When I try to download the LED blink sketch, the IDE sits there for about 10 seconds, then displays avrdude: stk500_getsync(): not in sync: resp=0x30 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

Has anyone else had this problem on a Windows platform?


Edit: I was finally able to get communications between my laptop and the Arduino working. I had to select COM4 in the IDE. COM1 & COM3 are listed as available, but didn't work for some reason.