Suddenly hotmail opens in a new window instead of a new tab. The box for open new pages in new tabs is checked.

Same problem - highly annoying

Also having same problem.

I'm having the same annoying issue only with hotmail. Is there a fix to stop this from happening?

I also have the same problem. In addition, the navigation and bookmarks toolbars do not show even though checked in the View menu.

Hotmail may have changed their software recently to open an email message in a new window, and also to block the toolbars from showing in that new window. They may be using JavaScript to open that pop-up. Or they may have come up with a way to overcome certain Firefox preference settings. (I don't know which it might be, I quit using Hotmail back in 1999, when I took the "training wheels" off my PC and I quit wearing short pants. ;-)

1. Tools > Options - Tabs You can select Open new windows in a new tab instead, and see it that works for you.

2. The JavaScript Options extension adds options to Firefox's JavaScript Advanced dialog window (Content tab in Options), which allows you to override websites that suppress the Toolbars in pop-up windows. https://addons.mozilla.org/en-US/firefox/addon/6527

Having the same problem. I have all ready done the solutions you've suggested. Didn't help one iota.

Having the same problem. Very annoying. Had already tried all the solutions "the-edmeister" suggested.

Btw, I'm very happy for "the-edmeister" that he has taken the training wheels of his pc, but the fact remains that firefox is having an issue with one of the most used websites in existence. That's a firefox problem, not a user problem.