Time's Battleland blog looks into the issue:
Military mental-health workers constantly try to reduce the stigma associated with mental-health ills, and one way to do that is to not term the problem a disorder.
Some veterans agree, but others -- fearful the name change is simply a way of minimizing what they're going through -- don't. "It's a double-edged sword," a long-time Army psychiatrist says privately. "We're trying to reduce the stigma associated with the condition, but it's in the DSM-4 [the American Psychiatric Associati0n's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), the accepted roster of various mental conditions] as PTSD. And some veterans fear that deleting disorder will jeopardize the VA benefits they get for it."