Normally the EV service account should NOT be a domain admin, see this technote:
http://www.symantec.com/business/support/index?page=content&id=HOWTO28135
Are you connecting to the EV resources with the EV service account, or with the BE service account ?
If you use the BE service account, add the following permissions in EV:
Extract of Steps:
1) In the EV Admin console, right click on Directory on the EV server and select 'Authorization Manager...'
2) Expand 'Definitions' then right click on 'Role Definitions' and select 'New Role Definition'
3) Give the definition a name like 'Backup Role' or something else descriptive for the Backup role.
4) Click 'Add' to add tasks, click the 'Tasks' tab, and add both 'EVT manage Index Location Backup Mode' and 'EVT Manage Vault Store Backup Mode'.
5) Click OK
6) Right click on Role Assignments and select 'Assign Roles...' Locate the Role Definition you just created and check it.
7) Click OK
8) Right click on the Role Assignment you created and select 'Assign Windows Users and Groups'
9) Add the Backup Exec ID to the object list and click 'Check Names' to be sure that the name is resolved
10) Click OK
