Thank you David!
If you could download the model and check it yourself - there is something else than OpenGL messing up. If I export the model geometry to a new file, then everything is ok.
If I export the model to sketchup from old file, the file is unusable - check the image (this is taken from another file, where I had the similar problem).
If i export the model to sketchup from that new file, everything is fine.
So I thought, that I would use the new file, but copying the info from old to a new file takes quite a lot of time. Still - I did it. After finishing with all the importing (schedules, worksheets, details, sections, elevations, layoutbook) the trouble was back - the file was again messed.