I've seen this problem when using @font-face generators that remove font hinting...

		justinweiss on April 7, 2013 \| parent \| context \| favorite \| on: Recreating the Reeder Two-tone Horizontal Rule in ... I've seen this problem when using @font-face generators that remove font hinting to save space. Last time I used FontSquirrel's generator, I had to specifically unset the option to remove hinting in order to get the fonts to look right on Chrome on Windows.

Aha thanks for the insight, I'll know what to suggest now when reporting this to site owners.