Just so you know, I could not replicate your problem... I'm not sure, but I think that site is safe, and it appears this was a unique issue to your machine. My guess is there was a glitch in your Firefox install.
Again, just a guess. I'm glad you're back to normal!
The way your computer was behaving was almost like what it does with the add on FF has that is a Boss button, or Panic button. When clicked it takes you to your home page, or a page of your designation.
You didn't by any chance have that add on did you??
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