a few minutes ago my pc freezed, so I rebootet and conected to the internet and after a little while i opened the client again to view the progress. but then i saw that the client was crunchimg a new model. So is that normal?

No. Take a look <a href="http://climateapps2.oucs.ox.ac.uk/cpdnboinc/forum_thread.php?id=116">here</a>. Your are not alone.