OP: bit of a guess but it could be due to Prune's recently introduced (ostensibly click-counting) mirror / link system. Here is a link from another thread I just copied as an example:
Code:
http://apicdn.viglink.com/api/click?format=go&key=1e857e7500cdd32403f752206c297a3d&loc=http%3A%2F%2Fwww.pprune.org%2Fcomputer-internet-issues-troubleshooting%2F530680-skydrive-picasa.html&out=http%3A%2F%2Fwindowssecrets.com%2Fforums%2Fshowthread.php%2F144077-Here-s-how-to-force-windows-live-mail-2o11-to-resize-attach-photos-like-oe&ref=http%3A%2F%2Fwww.pprune.org%2Fcomputer-internet-issues-troubleshooting-46%2F
As you can see the click is, as far as I can tell, counted once by "viglink" and once by Prune's vBulletin. (disclaimer: I really am not an expert in this area)
Such aburdly long URLs and/or large number of redirections might cause a problem with an iPad.