Problem with new AVR-ISP500

I got a new AVR-ISP500 today from Sparkfun. Intending to use it on OSX w/Arduino and with AVRStudio under Windows.

However, it doesn’t seem to work.

The setup : ATmega644P plugged into STK500 board ( socket 3100A3 ). Plug AVR-ISP500 into sprog3. avrstudio will detect the programmer, but cannot read the chip ID.

Arduino just doesn’t work at all ( tested under OSX ).

If I switch back to the onboard programmer on the STK500 and use a USB/Serial adapter, it works fine so I know the cheap/socket/board are okay. I bought the AVR-ISP500 because the STK500 is kinda clunky to use.

Any ideas? Did I get a bum programmer?