Portal Activity Report - timeout and huge load on ldap

Hello,

I created an activity report to count the users of a certain group which have logged on to our portal in the last 2 years.

Unfortunatly this iView times out after 5 minutes (time limit of iview has exceeded, or something similar). I then embedded the iView into a page and set the properties com.sap.portal.page.PageTimeout to -1, and allow_browser (client-side-caching) to no, but unfortunatly this has no effect and time out occurs again.
Then our ldap administrator informed me of massive requests coming from our portal, causing a huge load on the ldap. And it seems that these requests continue even after the iView has timed out.

My questions are following:
1) How can I get the activity report not to time out, but keep going until a result can be shown?
2) How can I trace or monitor the started activity report, and if necessary, stop it?

Thanks in advance,

Christiaan Hilkman