If you had a combination of Softimage 2010 and Softimage Advanced 2010 licenses, you will be getting two separate serial numbers for Softimage 2011.

You’ll get one Softimage 2011 serial number for your Softimage 2010 license, and another Softimage 2011 serial number for your Softimage Advanced 2010 license.

Unfortunately, you cannot combine the two Softimage 2011 licenses into a single license (.lic) file.
Softimage and Softimage Advanced were separate products, that is why it was possible to combine the two licenses.

What to do? Contact your reseller or the Business Center and ask them to combine your two serial numbers into one master serial number for all your Softimage 2011 seats.