Possible bug in SDK? via NBI using add

When using the API call addProvisionedElement with the following parameters: (example below)

addProvisionedElement($net_id_soap, $mac_address, $site_name, $site_location, $site_contact, $auth_key , $service_plan, $vlan_profile_name, $full_management_soap);

When attempting to update site name, site location, site contact using a script similar to the perl example included with documentation, the information is not updated. Initially, it WILL save the information if these fields are empty on a SM, however, if we run this again to update the information, the original information for site name, site location, site contact is not changed.

1. Add an SM using addProvisionedElement(…) this sets the following (example information) in Prizm EMS:
-mac = A0B1C2D3E4F5
-site name = Test Site 1
-site location = Starkville MS
-site contact = John Doberman
-auth key = 0000000000000000
-service plan = Lowspeed
-vlan profile name = (empty)
-full management soap = 1
Then, Prizm saves the above information for the specific SM.

2. When Updating the information using addProvisionedElement(…) with the following information:
-mac = A0B1C2D3E4F5 (same SM… so this should update the current information that is set in Prizm for this SM)
-site name = Test Site Z
-site location = Fresno, CA
-site contact = Jane Collie

-service plan = Highspeed

Then, in Prizm the service plan changes from Lowspeed to Highspeed (as expected). But, The information for site name, site location, and site contact remain the same – no changes take place.

Is this a bug in the API?
Should using the addProvisionedElement call with the new parameters for site name, site location, site contact change in Prizm for the SM, or is there another call that is necessary to update this information???

Thanks for any help,