NASHVILLE, Tenn. -- Another problem has been reported with the Tennessee Lottery.

Video: I-Team: Powerball Ticket Date Causes Confusion

The I-Team has found an untold number of people may have thrown away winning Powerball tickets after being told they were not valid.

One man, who asked to remain unidentified, said when he went to cash in his ticket that he was told the ticket was invalid. He said it has happened to him several times.

"I was trying to redeem a winning ticket and was told it was not a winner," he said.

He's discovered a problem with Powerball tickets that the state has known about, but has never disclosed, the I-Team’s Nancy Amons reported.

On the back of the man’s tickets, a disclaimer tells players that they have 365 days to claim their prize, but the actual number of days was reduced to 180 in 2004. So even though the date on the ticket says it is valid, the computer reads it as invalid because its date has expired.

"Well, it's not a glitch," said Tennessee Lottery spokeswoman Kym Gerlock.

Gerlock said the Legislature changed the length of time people have to cash in their tickets, but the printed tickets were already in stores.

"We went and made every effort to go to 4,500 retailers and collect all of that old ticket stock with the old expiration date and replace it with the new," Gerlock said.

She said the lottery has only heard from a handful of people who ended up with outdated tickets.

The problem has only been reported in Tennessee because the paper the tickets are printed out on in stores comes from the Tennessee Lottery.

But how many more people trashed their tickets when store clerks told them they weren't winners?

"I don't know how many thousands of people could have been affected at $15 a pop," the man said. "I totally understand mistakes. I'm in business, small business. We've made mistakes before and had to take ownership of them, why didn't the lottery take ownership of those mistakes?"

Amons reported that upon asking a lottery representative why they had never said anything about the error and why it wasn't posted on their Web site anywhere, she was told that it probably will be now.

The Tennessee Lottery said it will honor the one-year expiration date on the tickets that say 365 days. But to collect winnings, people have to contact the main office of the Tennessee Lottery.

In an e-mail sent to Amons, Gerlock said that in general, 95 percent of lottery players claim their prize in the first 30 days, and 97 percent claim in the first 60 days.