Originally Posted by dgatwood
You may be making it mad by specifying a font variant with a font that does not contain an actual smallcaps OpenType feature. Try taking that out of the CSS and just specify the font itself. Worth a shot, anyway.
I had another look at the file and found out that you were absolutely right on the money. Subsetting the font with FontSquirrel must have removed the smallcaps OpenType feature, essentially converting it to regular font with small caps and old style numerals glyphs.
After removing font-variant: small-caps;
from the font declaration and the small caps style everything worked as it should.