eBay will do that if you are accessing an important page or if you are changing something on your account, even if you have "stayed signed in." Try visiting https://scgi.ebay.ca/ws/eBayISAPI.dll?ChangeEmail. If you visit the page, eBay will ask you to sign in. Most of the links on the Personal Info page will ask you to sign in if you click on them. Hope this helps.