I've been observing this behavior for over a year.
The page loads are SLOW on mobile devices..at least Motorola Droid. I'm pretty sure this is related to the ad server.
The problem is that that main content loads, then a LONG delay for ad retrieval. If one scrolls down to start reading the content while the ads finish, the page jumps back to the top with each ad getting done.
I'm explaining this poorly.
Imagine a page that periodically jumps in the window due to adding content at the top.
Patience is a virtue, and yes, I can wait until all the ads load before beginning to view. But...sometimes, the hang-up is pretty much 'permanent" ... the page never finishes loading. Then, it's stop and reload and hope it works better with the next ad in the rotation.
I cannot say if it is keyed to specific ads. I'll try to watch that (but if they don't load, I cannot tell
More of an FYI ...