The first update to AutoCAD 2009 is now available. Here is the Readme for this update, which includes a note that these developer-oriented fixes are included (as well as many more general issues):
.NET API
- When a .NET function with a LispFunction attribute has the return type as object, an exception is thrown in AutoCAD.
Visual LISP
- The AutoLISP Redraw function fails to hide or highlight objects.
