WLI 7.0 studio user getting deleted

[Mandar Gandhe]

Hi..
I have got a clustered WLI 7.0 environment including one admin server and one managed server. And I have created my own user to access the studio (with full permissions). This user is visible on the console once I create it using BPM studio.
But when I restart the admin and managed server, this userid is automatically deleted and I have to recreate it.
Does anyone has any idea what is the problem here ?
Thanks in advance
Mandar