Problem with external fonts (reading impossible)
Display of text in aftermarket.pl works fine on Debian 7.5.
Tested with webpage switched to polish and Opera's user interfacer polish.
The webpage uses Source Sans Pro as font, not a webfont!
You have a problem with the display of your sans-serif fonts or with the correct fonts substitution of your Linux.
Please check this in Shell with fc-list:
~ fc-match "Source Sans Pro"
DejaVuSans.ttf: "DejaVu Sans" "Book"