AdRotate issues

Hi, I use the plugin AdRotate to show some banners from doubleclick.net.

Is there a way to exclude a PHP echo to be cached?

The problem is that our Adverts get a report from Doubleclick with about 19000 impression, but in AdRotate we get about 90900.
AdRotate’s author say to use W3 Total Cache, but it give me a lot of CPU usage.

thanks, Luca