I have found what I think is a fix (or at least a stable workaround)... I wish I could take credit for it myself but I found it in the last few posts here:
http://forums.autodesk.com/t5/AutoCA...4310464/page/3
Based on the second option I've added the following lines to my acad.lsp file:
(arxload "aeccivilbase.dbx")
(arxload "aeccland.dbx")
(arxload "aeccmapcheck.dbx")
(arxload "aeccnetwork.dbx")
(arxload "aeccparampart.dbx")
(arxload "aeccplanprod.dbx")
(arxload "aeccpointcloud.dbx")
(arxload "aeccpressurepipes.dbx")
This seems to be working solidly. Etransmit is functioning with the Civil3D Object Enabler installed.
FYI the other option was to rename "C:\Program Files\Autodesk\AutoCAD 2014\AeccETransmit.dbx" to "AeccETransmit.old". This seemed to work as well but it just does not sit right with me. Seems counter-intuitive.
Anyway, hope this helps.