Generally speaking, your bank would use a cookie to store your card number (bad) or to associate your browser with its list of saved card numbers (less bad). If you have cookies cleared after each session, then you may be blocking this feature. To check your cookie handling for your bank's site, when you are on the site, right-click the page and choose View Page Info, then Permissions. Under "Set Cookies" most likely the "Use Default" checkbox is checked. The actual setting will appear in gray. If the actual setting is not Allow, then uncheck "Use Default" and check "Allow." This will take effect the next time you start Firefox or if you clear the site's cookies on the Security tab (View Cookies button) and then revisit the site. If the actual setting already is Allow, then some other feature (e.g., clearing history when you exit) or program (e.g., a security suite) is clearing the cookie. This article has more tips on troubleshooting problems with cookies that don't save: [http://support.mozilla.com/en-US/kb/Websites%20say%20cookies%20are%20blocked Websites say cookies are blocked | Troubleshooting | Firefox Help]. Any luck?