This is due to the cookies stored in your browser. The previous sign in has a cookie that has not expired. I do not know exactly how Google tracks particular account's login, does it do this in another browser?

Best case is to remove the account from the list of accounts at the next login to a google website, or by removing all of the cookies from the gmail site. Clear cookies and site data in Firefox

Да, проблема таки была в куки и в хранении истории. была снята галочка с хранения форм поиска или чето в этом роде