Have you tried to create the CGM from within NX? Simply go to...
File -> Export -> CGM...
...and if you're running in 'managed mode' (i.e., under Teamcenter) you should be offered a Teamcenter enabled dialog for entering the name of the CGM file which will be saved with the Item Master. If you don't see a Teamcenter-based dialog, then you will need to manually import the CGM file into Teamcenter after creating it in NX.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
