Gaming Firefox search bars

[Hakoda]

On some search bars in Firefox, it will display accented letters instead of English letters. I'm not talking about the search engines in the top right. I mean like search bars on sites which you can use to search that site.
One example is the search bar at the top of InsanelyMac.com. I get this:

On SparkNotes.com I get this:

The word I'm typing in is "Search".

I fiddled around with the Firefox font settings and when I go to Tools --> Options --> Content tab --> Font & Color --> Advanced --> Uncheck "Allow pages to choose their own fonts, instead of my selections above", the search bars are applied with a specific font and the problem is fixed. Anyone know how to fix this so that when that option IS checked, the problem does not exist.

I've tried downgrading to Firefox 3.5.4 or upgrading to Firefox 3.6Beta4, the problem is still there.

This has never happened before.

~ Jon