The date of your most recent missed payment is unknown.
If you missed a payment, your FICO score evaluates how recently that missed payment occurred. In general, the more recent the missed payment, the more impact it has on your score. In your case, the date of this missed payment cannot be determined.
Keep this in mind: If you ask the credit bureau to report a date for this missed payment, it may lower your FICO score in the short term. If the late payment on your credit report is valid, you should focus on continually paying all your bills on time. This will demonstrate a good payment history going forward.
I did find that I had one credit card with no payment history for a couple of months in 06, but I did not miss a payment on them as reflected in my other reports. Is there a way to contact EX and get a better explantation