This seems to happen from time to time, -- if you live in a new suburb the system may not recognize the code yet. That is, assuming you have got the letter/number... order correct. (1s, 7s, ls, 5s, Ss, 0s and Os often get mistaken for each other). You need to enter the postal code to verify the location, as you have already entered it in your ebay and paypal accounts.
So use the postal code from the post office nearest you. 🙂 Or your local City Hall (speeding tickets and property taxes, -- they'll find you), or public library, or some other long-standing close-by facility. Then correct it as soon as you can.