Roles and Permissions after auto shrink

Hi,

We have defined two roles in our database namely SUPER and SUPER1. SUPER access has all the permissions where as SUPER1 is given to the end users without the database alter,deletion,object designer permissions.

Two days back we were getting “Transaction log file error” for which we had altered the database by ticking the Auto Shrink option. With this the database got shrinked and the problem was solved. But all of a sudden, today we noticed that all the users with SUPER1 permissions is changed to SUPER permission. What may be the possible cause fa this? Is this because we altered the database with the Auto Shrink option?