Just spent almost two hours on the phone with Apple support after I had had the computer freezing twice while editing a excel document in Numbers.
During the time with the support I managed to identify that the computer froze every time I added two lines and started editing on the second line. The problem seamed to occur also when all data is selected.
When the computer freeze everything is frozen except the mouse pointer which can be moved and even change pointer while hovering over the Numbers window or the menu. I tried cmd-alt-esc but that did nothing and the only possibility was to hold down the power button and restart the computer (I waited as long as 10 minutes without any changes or even the clock updating).
I managed to duplicate the fault even when the content of the file was copied into pure text, by using cat in the terminal (TextEdit didn't support simple text files, and NotePad that was my favorite program on Windows...) After opening the text file I exported the file as Excel format from within Numbers and when opening the newly exported Excel file and started performed the same type of edit the computer froze again.
I do accept that computers freeze and that programs crash occasionally, but I did hope that I would get away from those problem when I switched over to the Mac. I have really hard to accept that a ordinary program such as Numbers even should be able to bring the whole computer to a stand still, and if it did the OS should inform me of the problem, I think that I would appreciate the blue screen next time I see it.
We will see tomorrow what Apple support comes back with after that they have got details about my system and the problematic file.