pay per click performance

We are using google, yahoo , etc.. pay per click advertising. We tried the 'web bug' trend and created a cooking on http://www.domain.com and then our shopping cart is on a (different) secure domain so we put a 'web bug' at the receipt page but since it calls back the original http://www.domain.com/tracking.asp page we get the box that asks if you want to display the nonsecure page on the secure page.

Any thoughts on how people working around this? Wouldn't they have to originally come from the secure page then to the shopping page so you don't get this? Anyone ever attempt this and have great success? Looking for some help.