When I tried those two links with Firefox 20.0.1, I didn't see any delays. You might want to try Chrome which you can download from http://www.google.com/chrome . Two other things you could do would be (1) clear your browser cache in Firefox and (2) boot to Safe Mode and check for viruses.
At some specific websites, my computer will freeze up completely for a good 4-5 minutes before allowing me to continue navigating the page. This happens at those specific pages consistently, the first time I visit them each time my computer is turned on.
Websites that I know do this, off the top of my head:
There are other websites where I know this has happened, but I can't remember them. Another note is that it seems to happen at only the first example of those websites that I visit each time I turn on the computer, the next ones run fine as far as I could tell.
Operating system: Vista 32