Hello. Working in Maya 8.5 on a dell Precision 690. Using Windows XP Pro. I am trying to convery a piece of geometry in to a subdiv. I had it converted earlier, then went back to poly to work on it (deleting inner faces so as to combine/merge with mirror image. Started getting bugs in the conversion between polys and subdivs earlier but seemed to get around it, or so I thought. Now I am stuck in a loop. here's where the loop starts: I try to convert this poly to subdiv and get an error message. Script editor tells me: "Nonmanifold geometry cannot be converted to a subdivision surface. // To clean up nonmanifold edges, use Mesh->Cleanup with the nonmanifold option. // " So I do. When I click "clean-up" the poly switches to component mode with two faces highlighted. I check and discover that the entire poly now has about quadruple the number of vertices, with 4 sitting in each vertice location. I select the entire poly/verts and merge them so as to get back to a clean mesh. This is where the loop ends. I go back to object mode, try to convert to subdiv and re-enter this loop. Anybody know what's causing this and how to fix? Thanks for reading. T