[...]
I increased those values now
\def\defaultwidowpenalty{9000} \def\defaultclubpenalty{9000}
and it works for all cases except one. So maybe I just go down the manual path ...
then try \clubpenalty=10000 \widowpenalty=10000 \brokenpenalty 0 Any change? TeX's paragraph/page breaking is a highly complex thing, there are lots of parameters to play with. For a complete refrerence you'll probably need Knuth's original TeX book. But with these three penalites above, you should be able to solve the problem.
... surprisingly it seemed to affect also the footnote problem. There is also only one case left. Are those two somehow related?
This is beyond my knowledge, but here is a guess: These are related, but only very deep down inside. So for most practical cases, these two are different things. Patrick