Ulrich,

i don't find it very surprising that at this stage the new OR is not working
fully with arbitrary packages. I guess however, that David Kastrup would be
interested in hearing about specific problems with minimal example files
(involving only one or two such packages).

anyway, i understand the reminder of your mail as follows (correct me if i'm
wrong): you tried to produce grid based typesetting using std latex2e +
multicol doing this by setting various spacing parameters so that they fall
onto an imaginary grid.

well first of all \multicolovershoot/undershoot was a somewhat rubbish idea
i guess and in fact i finally decided to change the default of one of them
(overshoot) back to 0pt even though that means an incompatible change.

the problem results from the fact that if you have only normal text (no
stretching etc) a positive \multicolovershoot can fool multicols into
thinking that n*\baselinskip-\multicolovershoot is a valid column height. if
you look through the recent bug reports on latex tools (something 3400+) you
should find a dicussion on that topic.

there is however another space being incorrectly added by multicols which is
1pt of \lineskip in certain situations. i will send you a new multicols beta
fixing all that off-line.

concerning missed parameters to set: in case of problem you might try
looking at the detailed page result using \showoutput that gives you very
precise information on the glues and kerns inserted and will help to trace
some unexpected space

frank