If you have downloaded http://www.mozilla.org/press/nytimes-firefox-final.pdf you may have surely noticed that no free pdf viewer can display it, not xpdf(so no kpdf nor gpdf), not gv(so no kghostview nor ggv)
Reading the comments on the news item seems nodoby cares for it ... But i do, why is one of the jewels of the Free Software promoting non Free Software pdf viewers, i'm sure it could have been generated in a way that it looked the same and worked on free viewers.
Update: It seems it works with gs 8.15, the problem is that CUPS only comes with 7.07, any idea if anyone is working on CUPS? Will they ever update their gs version?