Well, my first impression is the Page didn't load fully, as that's sort of what my Sites look like at home when my Internet decides not to work. I'm betting that's not the case for you, as (based on what you've said) this has been happening for a little while now.
When was the last time you cleared your Cookies/Offline Files/History? Perhaps something saved from FF got corrupt. That's a long shot thought, but as simple as it is, I have to ask. :/
I have no reason to believe Spybot would do this, it appears that it's blocking the "Banner" at the top, wherein your Links are just lined up on the left as if that Banner never existed, affecting the Dropdown Links as well. I could be wrong, not much experience with it, as I don't use it, but that doesn't sound like normal Spybot behavior from what I am used to.