This code snippet might help:

use DatabaseNameHere

go

EXEC sp_change_users_login 'REPORT'

EXEC sp_change_users_login 'UPDATE_ONE','user','user'

This worked to resynch orphaned logins for me. Just put your database name in line one above and your orphaned user name in place of the user in the last line of the script.

Cheers

M 🙂