Izumi Tsutsui wrote:

 > (kernel vs userland version mismatch?)

Yes that was the problem. After installing a 1.6ZK kernel
I was able to recompile the tools without problems.
I don't know where this version mismatch came from. Most
likely I've been stupid enough to install a new kernel version
without recompiling userland and then forgot about this later.
Thanks very much for your help.

Werner