NIS 2009 causes systemcrash

After installing NIS 2009 my system hangs after starting up and when I try to start any program. Restoring a registerbackup solves the problem, temporarely, after a day the problem is back. At the same moment when my system works I can restart as much as I want without any problems but if a wait a long while I got the same problem, then I must restore my register and then it works again.

Does anyone knows what can cause this problem?

Thanks for your help.