Number Crushing nonstop

Hello everyone

After return finally to Mac OS X and Apple (4 years really sad time with Windows), I meet a big problem with my really loved packet - Apple Works, actually with Numbers. Application nonstop crashes in random times, sometimes it's just click Space, Enter or anything. Usually when I left app in background and back to it after just few minutes. Always crash if it's longer than hour.

There is no crash report, any message about a problem, any thing :( so, I cannot send it to the support.

Can I resolve it somehow or it is a new skill in Numbers now?

Regards

Dawid