Thanks to all that replied, and special tanks to Terry who was the first to identify the problem & solution. Go to: Tools > Parameters. In the lower-right of the parameters dialog, change the parameter types (pull-down menu) from Main to Alternate Mass Properties. Parameter PRO_MP_SOURCE should be set to GEOMETRY (ours was set to PARAMETERS).
Gerry Champoux Williams International Lead Engineer 2280 E. West Maple Road Information Technology Walled Lake, MI 48390 ' (248) 960-2816 7 (248) 960-2607 * - <">mailto:-> * www.williams-int.com