Ads not showing up (too many?)

[MikeLR]

Hello,

We want to add ads to all of our sub-forums (different brands of products), we are using vBulletin 4.2.0.
There are a lot, 150-200, which allready are added in the admin. All separated so we can add banners of stores to the brand they sell with the "only show at specific forum"-option.
We are using a script for the banner rotator so we can have like 5 banners in one section.

The problem is, after adding al those ads, we can't get them active.
It looked like a problem of time-out so we set that up to 5 minutes. That was the solution to avoid the time-out, but the ads are not showing up?

Then we decided to test it and activate it one by one. This works in the beginning, but after like 20 ads activated the time of updating is getting longer and longer and after like 30 ads activated they all disappear...

Is there a limit of activated ads in vBulletin and is there a solution to get them all activated and keeping the admin panel fast?

Thanks!