That's because the Levin-Graham-Kyl amendment prevents the detainees from seeking judicial review of anything but their initial designation as an enemy combant and a review of any military tribunal conviction. There is no way for them to challenge the conditions of their confinement, even if it amounts to torture.

450 Law professors signed a letter (pdf) asking Congress to repeal the Levin-Graham-Kyl Amendment from the defense authorization bill.

...The Graham-Levin-Kyl Amendment opens a backdoor to torture: It would permit the CIA to cooperate with foreign intelligence services that we know use torture to extract evidence through coercion. That evidence would then be available as a basis for detention decisions.

“Congress is taking with one hand what it has given with the other,” explained Mr. Waldman. Never before in American history has a Congress put its stamp of approval on the use of physically coerced testimony to make decisions between liberty and imprisonment. Even in past times of war, this practice has no precedent.

“This bill will not put an end to physically coercive interrogation tactics that yield unreliable information, cautioned Professor Burt Neuborne, legal director of the Brennan Center and Inez Milholland Professor of Civil Liberties at NYU School of Law, “But it will erode our moral standing in the world community and subject our troops to almost certain reprisals in the future.”

Six retired federal judges wrote this letter (pdf) asking for the Amendment to be removed from the bill.

Joanne Mariner has more here.

The passed bill is awaiting Bush's signature.