Yes, I finally got it working. Seems that IBM has made a change to Lotus Notes up from release 6.5, since just copying the data over (no special dll copy needed) solves the problem.
This description is valid for the old version of cross over office only (below 2.1):
Notes starts perfectly, runs well without crashes. The only glitch that I saw was that the buttons have this kind of corrupted bitmap pattern on them, that sometimes disappears on mouse-over.
I would consider changing the status of Lotus Notes 6.5.1 on the base of this finding. It still does not install, mind.