In Firefox > Tools > Options, goto "Content", then look through the "Fonts and Colors" section. Make sure the "Allow pages to choose their own fonts, instead of my selections above" option is ticked under the Advanced button options.
In Language, make sure your default language is set.
You may have to restart Firefox to see if it fixes it.
Mark
Recently, I have become unable to "type" correctly into some text fields such as the search bar on Gizmodo.com . Not all fields are affected; for example, Google's search bar works perfectly fine.
I'm pretty sure this isn't a local font issue, I've look at them all and I don't see any corrupted fonts when previewed.
The problem is localized to Firefox. It doesn't occur in Internet Explorer.
http://www.postimage.org/image.php?v=gxN33jA
Windows 7 Home Premium 64-bit
Mozilla Firefox 3.6.4

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