When scp'ing some files from the laptop to my server I got the error protocol error: mtime.sec not delimited and didn't know what to do. Some forum suggested using "-v" as parameter for scp to get more info, and it indeed gave me enough of it to find the problem's source: On every login, fortune is executed telling me some nice quote. scp does not like it.
So instead of just calling fortune in my .bashrc, I check the $TERM variable now:
if [ $TERM == "xterm" ]; then fortune -s fi