Ah ok, so I simply copy the code to the bottom of the template and that's it? That's what I did before, but like I said, I had the feeling the code was causing weird loading errors this time around. But I have to say I was using a different code back on the v3 version of vBulletin, so maybe it's not the position within the v4 version, but the code itself, or rather the file on the ad-server.
But as long as it's ok to just copy the code into the template I'm relieved.
And thanks for the super-quick response. Much appreciated!
Just one more thing, as you said, if I put it into the head-include, it will be loading on all pages? Because that's actually better than just on forum-home and showthread...