Renamed user doesn't work as expected

Hi all,

We are encountering an issue for which I haven't been able to find any solution online. I will try to give you as many details as possible.

- system version: NAV 2009 R2

- User accesses NAV only for Vendor Approvals

- User got created in both SQL and Active Directory with an extra -r in their name (misspelled)

- When the mistake was rectified, the user and login have been renamed

- User was able to open NAV but would see 0 Vendor Approval's. When clicking on the task, it takes her to the Vendor Approval list but the filter is her misspelled previous username. She can remove the faulty -r at the end, but when she tries to approve the system is saying she doesn't have permissions to do so although it shows her as being logged in with the correct name

- Both login and user have been deleted and recreated but to no avail

- The only solution that works is to remove user from Windows Logins -> Synchronize all users -> Add user again in Windows Logins -> Synchronize all users  (this action has to be performed every morning, because somehow her old user comes back to life during the night...)

Did you ever encounter something like this? Do you have any ideas how it could be fixed?