I'm on a web site and I click on the x to close the tab. Instead of the next closest tab showing on my screen, some other web site comes up. Like just now, I clicked off of Facebook and Ebay appeared. I had three other tabs and none of them were Ebay. I'm running a 64 bit unofficial version of Firefox called Nightly. Maybe it's a flaw. Or maybe it's some new way to slip in some advertising. It's kind of annoying. Has this happened to anyone else?