basic

Basic Latin (Unicode block) problem?

Recently my web browser (chrome) started displaying little blocks instead of text.

Here I have an example of the problem (from the yahoo login website):

I have no idea how to solve this and since this is sort of a 'typographical' problem I thought you guys might be able to help.

Here is a larger image of the symbol:

I can still copy and paste the text and it will display the right text, so I think it has to do something with the font. Anyone have any idea what might cause this problem?