iAd Banner causes major FPS drop

iAd Banners are causing a really big performance drop. They cost around 20-40 FPS depending on if the banner is animated, when the banner is first shown the slowdown is at worst. I’am not sure if this could be considered a Bug, since i have read in different forums that is a engine independent problem caused soley by the iAd’s.
But it would be nice to know if there is any solution for this issue.