The Placer County Transportation Planning Agency has lost its online lease, and it says the new occupant has some nasty habits. The new owner registered from China and is illegally using the appearance of the old site to trick visitors into viewing advertisements for everything from diets to auto parts. For the time being, the correct Web site for the government agency is at pctpa.net. But it’s easy to be fooled by the old site at pctpa.org. The sites look virtually identical, but the news links are old. Many other links lead to advertisements or content on subjects like car audio systems and automotive repairs. The root of the problem is simple: Placer County didn’t renew its claim to pctpa.org in time, and another bidder snapped it up. The agency is trying to buy back the Web site, with a price in excess of $1,000 mentioned, said a spokeswoman.