Pressing the "forums" button in the top bar of the front page from my iPhone 4 opens up the same link as the current sponsored app (currently the monster truck one). Doing the same on my iPad/PC simply takes me to the forums. Not sure what's going on there, but it's really stupid, especially on a device that force-opens the App Store for you. Hope it's unintentional and an easy fix. Just to expand: it opens the App Store then, when I come back to Safari, it starts loading the forums with no further input from me, the same way a pop-up would behave.
This was unintentional and was due to a DOM tree event bubbling issue, though it's curious why it just, all of a sudden, became a problem. At any rate, the mobile website has been adjusted in structure to avoid the issue. Please let us know if you find any ill-effects that the fix may have caused the we've not seen. Looks ok from here. Thanks. bp