I suppose this is a variation on the "not getting booted out of the ancestral lands" bug, but with a twist.
I was walking through Xalanga - Fervor Track (I think B, but I'm not 100% sure) when it seems like I ran out of time at the same time as I clicked on the signpost for the next street. And I ended up in Fervor Track C.... but buried in ground. When I started walking, it looked like two streets materialized simultaneously - one at "regular" level, and one below ground - including trees and a shrine to Mab. Once I walked "through" the ground to a regular sort of space, I was able to jump and interact as normal.
Anyway, when I clicked on the next signpost, the game froze, I closed the window and logged back in, and I appeared in Vada Widens, along with a message that I'd last been there two minutes ago. And, Vada Widens has a shrine to Mab.
No idea if this is reproducible, or whether it's just clicking on the wrong thing at the very wrong time, but I thought it was worth noting in case it comes up. Oh, I'm running Firefox 7.01, Windows 7, and Flash 10.3.183.10 in case that's of any use.