Almost five years ago, I ran across an issue where the SHIFT key was not working as expected, specifically when trying to "hot grip" multiple grips. At the time, I found that Raster Design had hijacked the shift key to allow for image selection.
If you have Civil 3D 2011 and need to import raster images like MrSid and ECW format (who doesn't?), then you will need the Raster Design Object Enabler since there is no Raster Design 2011 yet. But wait, there is no Raster Design Object Enabler for 2011 either. Oops.
Fortunately, someone figured out how to hack the 2010 RD Object Enabler so that it will work with Civil 3D 2011, and the resident MAP guru, Murph himself, posted the solution over a month ago (AutoCAD Map 2011 needs this hack too...). Since the 2010 version works for 2011, I'm not sure why Autodesk has not written an installer for it. IMO, support for these image types should be built into Civil 3D and Map anyway.
I do not have any information on when to expect a 2011 version of Raster Design or the RD Object Enabler.
If you are using Raster Design (ARD), take a few minutes and explore the ARD Options dialog (command name IOPTIONS).
We frequently edit raster images using Raster Design (ARD) by merging vector linework back into the raster image. In almost every case, we wish to discard the vector entities after performing the merge.
I have ran into this problem a few times now so thought I would write it up... If you have AutoCAD or a vertical installed along with Raster Design, and your Shift key stops working for things like "Shift+Pick" to remove objects from selection sets, or "Shift+Pick" to make multiple grips hot, then this might be the solution. Run the command IOPTIONS Go to the User Preferences tab