are you using a Rig for this? watch this for instructions on orbiting around a layer in Ae: After Effects CS5.5 Orbit camera rigs tutorial
if this still does not help, please provide more information on what exactly are the steps you are taking and what result you are seeing. show some screenshots and provide some information about your setup.
Adjust your group center/ anchor point in the E3D effect or in the 3D editor.
Hope you're doing OK with your project. Did you solve this issue yet? Please let us know!!