Oh wait, you're in the Windows Start menu...
I can remove the DST files from there, but it has no effect on the Recent Docs list inside of C3D. The DST files are still in there.
And as I just discovered, DST files might magically reappear in that list for no apparent reason.... I deleted the DST files from the Start menu for C3D 2011, but the next time I started C3D, the DST files appeared in the list again for no apparent reason.
Let me check around to see where that list may be residing. Stay tuned.
OK, the DST files get re-added to the list when the SSM is opened. If the SSM is docked to the side and set to auto-hide, you'll see the DST files reappear in the Windows Startup list during C3D's startup. Otherwise, they reappear the first time you open the SSM.
Talking to the members of AutoCAD team I am finding that this issue is reported to the development as a core AutoCAD issue. No information when or will it be fixed any time soon. BTW, The recent file list is stored in registry: HKEY_CURRENT_USER\Software\Autodesk\Auto
The best thing to do here is to pin recent drawings so that they do show up. Hopefully this will push DST files down the list.
Nice bug.....could quickly make the recent documents list pretty pointless...!?!?!?!
Very irritating bug but no solution - here's hoping for Civil 3D 2013...........