PR5 doesn't mean much as far as SE goes for me either. I have 4 PR3 domains that rake in 10 times the SE traffic I get for this domain! The only reason I'm peeved is that my other domains don't have PR5 and they have better quality backlinks coming into them lol!
I am 90% certain that the PR of this domain is more from the outgoing links - mostly to major newspapers around the world, than anything else. I have another site listed in same category at DMOZ - Adult/News/ which has a PR4 despite over 8k in backlinks.
Yahoo says 2,200 backlinks for sexinmedia.com - but most of them come from my own lower PR sites.
Lets see if the PR holds in a couple of months. I'm not really promoting this domain for now.