This discussion link provided was dated 2007, we expect some updates would have happened, so would like to know the latest information, which is close to within a year.
AutoCAD LT version is not currently supported with Windchill Workgroup Manager. We support Standard AutoCAD, Mechanical & Electrical Versions. Please refer to WWGMCompatibilityMatrix.pdf (ptc.com) for the latest updates on the 3rd party CAD Applications with Windchill.