Edit: scratch that. In reviewing the network scan code I see I
remove the local PC IP addresses as an optimization. So for now (until I fix that) you'll need to quit MultiMiner and edit the NetworkDevicesConfiguration.xml file (found in %appdata%\MultiMiner on Windows) and add an entry manually, e.g.:
10.X.Y.Z
4028
true
false
Got ya... I set-up another computer to use MultiMiner directly for all the other hardware I have, and the CGMiner process is being detected there (as a network device), so as you said it's the local IP address thing, since the other computer is seeing it.