CARY, N.C. — A scam is getting more and more attention nowadays. Advertise something for sale online or even in the newspaper, a buyer agrees to a price and sends a cashier's check which is supposed to be just like cash. The problem is the check is a fake, but it is so convincing that even banks are faked out.

Lewis Smith still has a custom-built mandolin. Last April, Smith sold the mandolin and a banjo online to "Victoria" for $2,000. Smith received a cashier's check from someone else for more than $15,000.

"Victoria" told Smith it was from someone who owed her money and asked him to just wire her the $13,000 difference.

"I thought this was kind of suspicious, so I said my best bet is to take it by the bank and see what the bank thinks about it," Smith said.

Smith took the check to his Wachovia bank branch. He said he showed it to bank managers and told them the whole story.

"The two of them together said 'No, we don't see anything wrong with this check,'" he said.

The bank held it for eight days, then the customer service manager called Smith.

"He said, 'Mr. Smith, the check appears to be fine. There's nothing wrong with it that we can see," Smith said.

Smith waited two more days, then had Wachovia wire the $13,000 to "Victoria."

"That's when the dust hit the fan," Smith said.

Not two weeks later, Smith's bank account was cleaned out, with a negative balance of $9,200. Smith called Wachovia.

"That check bounced after you held it for 10 days to make sure it was good. Hello?" Smith said.

Wachovia sent letters, saying it was Smith's "responsibility" and threatened "action" unless "payment arrangements" were made. Five On Your Side called Wachovia.

A representative would not talk about Smith's case, but after calls from Five On Your Side, the bank dropped the $9,200 negative balance and sent Smith a check for more than $4,300.

The more-than-$13,000 resolution sounds good to Smith. He just wishes it never happened.

"I had no way of knowing myself if the check was good and I depended entirely on the banking system, but the bank's system failed," Lewis said.

A note about "Victoria," Five On Your Side found she used a couple of different last names on the e-mails she sent, so chances are they are not real. A Wachovia representative told Five On Your Side the bank assesses situations like this on "a case by case basis."

The bottom line is anytime, anyone sends a check for more than the amount, be leary. According to the North Carolina Bankers' Association, the best thing to do if you have any question at all about a check's validity is call the issuing bank. Look up the number yourself. Do not use a number on the check.