Melissa Haberzettl, 29, of Colorado Springs, Colo., knew something was wrong when the county coroner ruled that her 3-month-old son, Jake, died of viral pneumonia in February. Death by pneumonia is very rare for otherwise healthy infants.

"My husband and I are both physical therapists, so we have many connections in the medical field who all agreed with us that this was a ridiculous diagnosis," Haberzettl said.

Jake had no symptoms of illness when he was put to bed. There was no fever or change in his eating patterns. "The coroner told us that Jake probably did not die of viral pneumonia. But there was a virus present in his system, so that is what they were calling it," she said.

Haberzettl convinced an outside expert, Dr. Henry Krous of San Diego, to consult on the case and eventually convinced the coroner to change the diagnosis of SIDS.

"I find it rather frustrating," she said. "Things that used to be called SIDS are being called something entirely different. I don't know why. How can it be called one thing in one county and something completely different in another. It's crazy."