Nope. Sorry. No dice. Does it here at XF, and at my 1.1 beta test site. Zoomed-in or out doesn't seem to matter.
It sort of splits the process into two stages:
1) Tap alert link - get the ajax animation to show it's querying - link goes into "hover" style - and then it stops there.
2) Tap again and URL bar briefly pops down and folds away - then alerts listbox displays
Seems to do this for inbox too.
I can live with it if it's just me, but I thought I'd mention it in case it was affecting other people too.
iPad 2, iOS 5.0, Safari with and without using tabs, clicking on xenforo.com / xenfans.com on a new alert, the alert dropsdown and i can click on an item and it loads. It doesn't seem to require two clicks.
Clicking twice loads the full alerts page.