Something wrong with wordpress index.php?

Hi everyone,

I searched the forums but didn’t seem to find a remedy for my current problem.

So this is how it goes:

If you look at my index.php at http://www.musavis.com you’ll notice that the first post content is Tahoma (normal) and all of a sudden you see that both sidebar text and posts below the first post are all BOLD. What’s interesting is if you go to the next page or if you add a new post the last post in the first page will move to the 2nd page but this time it’s not bold. This problem is only in the first page and I don’t know how to fix it. Has anybody come across this problem or know the solution to it?
As far as I know this is not a template error because even if I change templates the problem still persists.

Thanks in Advance.