A bit hard for other buyers and sellers (the only people here) to say without any details
Did you ever have a gmail address that was used for eBay?
Does anyone else in your home use the same computer/device and may have left the 'remember me' box ticked last time they used eBay?
Is the Gmail address already there, or does it change what you put to Gmail, or does it re-direct you to another page altogether?
