Yes we are running DBCC DBREINDEX daily during that time as part os our Maintenance

I mean any specfic event to be captured??

Thanx

Well this is a production environment. I know SQL profiler EATS up memory. Is there any other way??

What is the size of the TL at 9pm? And if is small then something is happening in those hours, you may want to set up Profiler to catch what...