OS X :: Opening URL Links From Mail 4.3 & Finder?

For the past few days, when I try to click on a URL link from an email, Firefox will open up but not to the link. I have to right click and copy link and then paste it into the location bar. Very frustrating.

I have also noticed that when I double click on a .html file from Finder, I get a pop up window asking me if I want to open it up and I click "yes" (this is normal), however, once I do that, nothing happens, but if I double click it again, it will open up in Firefox. And each time I do that for each file, the file is not opening up in a new tab, but in a new session of Firefox (my preference for this is set to new tab instead of new window).

I have checked both Firefox and Mail preferences but can't find anything about links to assist/guide me. Any and all advice is welcomed because I am stumped.