The PC speaker is normally meant to reproduce a square wave via only 2 levels of output (the speaker is driven by only two voltage levels, typically 0 V and 5 V).
For example, if your payments for March and July 2010 were each one month late, the report may continue to show (for seven years from the date after each payment was due) that you were 30 days late twice in 2010, even though the tradeline for that account also shows your payments for the rest of 2010 were made on time.
In your case, the creditor is Macy's. Once it has been reported, a late payment can stay on your credit reports for up to seven years. After that they must be removed in accordance with the Fair Credit Reporting Act, or FCRA. Derogatory entries can do a lot of damage to your FICO credit score.