I seem to be having the same problem although you are at least able to view a tiny center portion of your text and I am unable to see anything as if the padding around the field pushed the inside into nothingness.
http://austinwebdesign.us/checkout/
its really strange. The only WOO input field that seems to be ok is the special coupon code field and I checked my contact page and those fields seem ok. I also looked at all of it in firebug and the css seems ok too.