When I create an Object Data Table in an attached drawing, the Object Data Table is deleted when I open the drawing into a work session. Select from the Map menu pulldown, Tools, Drawing Cleanup.
All tools incorporate the use of a user defined tolerance setting.
Additionally the user has the option to convert all select lines, 3d plines, circles, and arcs to polylines. This issue has been addressed in the AutoCAD Map 2000 Release 4 Service Pack .