When you ran CIFS setup the first time did you select option 1 (AD) or option 2 (NT)? If 2, then you will be required to:
CIFS setup (select option 1 this time) and it will find a computer account. Re-use it.
If you selected option 1 during CIFS setup, then no changes are required and it will work.
Professional Services Consultant
970.214.8188 - Mobile
1.888.463.8277 or now.netapp.com <http://now.netapp.com/