Win7 64bit. Civil 3D 64bit.
I have the same problem after using Data Connect to add a polyline shapefile to my drawing.
I would roll off the Data Connect Diloag an onto the shapefile...HANG...CRASH.
Thanks to Alfred's suggestion I checked ROLLOVERTIPS and SELECTIONPREVIEW.
ROLLOVERTIPS was set to 0 already, SELECTIONPREVIEW was set to 3, I changed it to 0.
Everything works good now.
I checked these two settings in Civil3D 2011, where I have no problems with shapefiles, and ROLLOVERTIPS was set to 0; SELECTIONPREVIEW was set to 3. Those same settings will not work in Civil 3D 2012.
Win7 64 bit & Civil3D 2012 64bit
Further testing shows that if I use a regualar AutoCAD template when using the Planning andd Analysis' Data Connect to bring in a shapefile, it will hang and crash.
If I use a civil 3D template, no matter what the SELECTIONPREVIEW is set to, it will not hang and crash.
In Civil 3D 2011 64bit, it works no matter which template I use.