Bug#154251: It's the xbase-clients package

[Jan Harnisch <harnisch@fgb.mw.tum.de>]

Come on guys, talk to me... are you all on vacation or what? ;-)
In the meantime I have installed X on one of my PCs where I experienced
this problem, and like magic it worked. I checked the packages that were
installed and repeated the procedure installing the packages one by one.
After installation of the xbase-clients package, logging in from remote
worked with no problems.
It seems that, even when configured with "ForwardX11 no", sshd tries to
activate some program (xauth?) and starts getting mad when it cant find
it.
So long, I think having gotten up to this point, I will leave the rest
of the work to you :-) Hope I could help a little bit.
Bye and best regards,

Jan