I have recently added a new site that has a forum directory in the root of a php based domain. I see that the installation instructions are different for the forum. I have followed these instructions for the forum, then followed the standard installation for php pages outside of the forum. I end up with 2 sets of network files on this domain. 1 set in the root and 1 set in the root of the forum. Is this correct? All ads seem to be displaying well. However I notice the odd time a text banner displays with my text links? I am running 5 ads.
You really should consolidate the two ad_network.php files to just have one. Have your forum specifically include the one on the root of the domain for example. If you don't, your server is going to make twice as many requests to the ad server.