Doubleclick is some sort of adware/spyware. I'd run a scan, use Spybot or something. If you've installed any new downloaded programs lately, I'd be highly suspicious of them.
I had a similar problem a while back, I'd be over at the IMDb, do a search for a movie, and get transferred to some weird page telling me they couldn't find what I was looking for. I traced it back to some advertising thing that was owned by Google. I un-installed the Google pack, ran a scan, and that seems to have eliminated the problem.
The exact same thing happened to me, I get at the imdb!
It seems to have gone now, but it was very annoying !