I have been getting this a lot. This is in R2012, although I do have Civil 3D installed. Something is in my drawing that is causing AEC to load, which does, is known to, cause all sorts of issues:
Enter new value for INSBASE <6.4556,-337.0410,0.0000>: *Cancel*
Command: Loading AEC Base... Loading AEC Base Extended... Loading AEC Project Base... Loading AEC Schedule Data... Loading AEC Architectural Base... Failed to register DWS file support for eTransmit.Loading AEC Base UI...
One thing I am puzzled about is why setting the insertion base point shoudl demand load AEC!?
Hopefully Autodesk will fix this soon.