mail server username reverts to 'admin' when setting up mail queue

[steveparks]

Hi

Has anyone else experienced this, or got any ideas on how to fix it please?

I'm trying to set up a new mail queue for a new department. I enter all the details, save them, and then run the cron script manually.
It gives an error for this mail queue saying that the login details are incorrect.
I go back to the mail queue setup and the mail server username is now showing as 'admin' instead of what I had typed there.
No matter how many times I re-edit the username, it keeps changing it to 'admin'
I'm running 3.0.82 on RHEL3, PHP4, MySQL5, accessing it via firefox.

thanks for any help
Steve