Got it working!!!
It is explained here:
http://www.mail-archive.com/avrdude-dev@nongnu.org/msg01800.html
Incidently, I already found that page before asking here, but I did not fully understanding the implications.
I realized that the config files contained a lot of pre-configured board types of which many of them was of type parallel, having this line:
type = par;
Now, what was certainly not obvious to me was that avrdude failed when reading these config lines because of the missing system parallel port,
even though I did not specify any of the programmers in question!
I think this behaviour is downright silly, but well, I replaced all occurences of
par; with
serbb; and then it worked.
I have even found that I don't need the reset line which is necessary on my desktop pc.
Thanks for your reply, kg4wsv; even though your suggestion did not help in itself, you made me look once again at the problem with fresh eyes
