OT: unable to reprogram ppm encoder module with av

Hi there

I know that this is not directly related to arduino, but I thought that some clever guys might still have a hint for me.

I ordered a 8 Channel PPM Encoder and now I'd like to change the software on it. I connected an AVRISP mkII In-System Programmer to the ISP Pins, but the only message I get in avr studio programmer is:

could not enter programming mode.

I already tried to lower the frequency of the programmer. The led on the programmer turns to green which is correct. I flashed other mc's successfully with the same programmer.

Is there anything special I need to take care of?

You can find the schematics and some infos here: http://store.diydrones.com/ProductDetails.asp?ProductCode=BR-PPME

The board is based on a ATMEL ATMEGA168/328 AVR processor.

Thanks a lot!

/Edit: Sorry for wrong forum, this should be in hardware