Mouseover popups missing

[Sethala]

So, it used to be when I visited this site, I could mouseover a few things (such as the different sections of forums, or a person's preferences in their O&Os), and get a bit more detail about them.  However, it seems that's somehow gotten turned off, and I'd like it back on, but I don't know how.

Currently I'm using Firefox version 15.0.1.