Atticus - does this describe the phenomenon:
"... for both customer and admin logins, only the very first attempt with correct data input is bringing up the message 'There was a security error while trying to login'. The password asterisks stay in place, and simply tapping return once more then gets you in to the store/admin with apparently full functionality."
Not sure why that happens, but it can be lived with if so ... (dscvry post above fr June 2008) - sweet if that's the issue.