Problem with Hourly Cleanup #2
 

Hello.

I've got a problem with the Hourly Cleanup #2 of vBulletin. Before it was set to start 2 times a hour* but every time u wanted to check PMs or to go to the user panel (between xx.30 and xx.40 hour* so for 10 minutes) u couldnt get in. Now i set it to start just at 4 o'clock and its unbelievable how high the serverload gets (for hours* till 9 o'clock) and its often too much for the server so im getting http:ERRORS from 8-9 o'clock.

My Question:

What does the Hourly Cleanup #2 exactly do? And what can i do to solve the problem?