Newly minted MMAMania has the info:
"The Muscle Shark" tested positive for a banned illegal steroid known as "Nandrolone" after his successful 155-pound title defense against Hermes Franca at UFC 73: "Stacked" back in July. Franca also tested positive for steroids; however, he admitted to the charge and accepted the punishment ($2,500 fine and a 12-month suspension).
On the other hand, Sherk has denied taking any banned substances and has stretched out his appeal to put together a solid defense.
If the ruling is upheld Sherk will more than likely face a similar fate as his UFC 73 counterpart. In addition, UFC President Dana White has indicated that he will be stripped of his title.
As hard as Sherk pushes training and supplementation, your forgiving mind makes you believe this is all some sort of misunderstanding. But folks like Fightlinker and MMA Analyst have shown the scientific evidence (and the legal precendent) are not in Sherk's favor. Stay tuned.