Maybe this is an old exploit but today I have noticed 10 - 15 of my older wordpress blog have been infected with some kind of redirection exploit. Basically if you type the url in the address box and go directly to the site everything is fine but if you search your blog on Google or Yahoo and click on one of your sites listed urls you are redirected to a site (www.your-needs.info in my case) which seems to be a parked landing page. The only reference I have found to this exploit was on a Spanish language blog dated a couple of days ago so I'm assuming this is recent? Anyway upgrading to 2.5 fixes the issue.