AutoCAD Civil 3D :: Import STM To 2014?

I'm using C3D 2014.  I created a pipe network, exported it to Hydraflow Storm Sewer, perfermed an analysis, and have HGL/flow data.  When trying to import the .STM file, nothing happens.  Here's what it does:

1)  Import .STM into a Blank/New Drawing ->  Creates a pipe network with correct IE, Size, and HGL/Flow Data

2)  Import .STM into design drawing -> Choose to Update Network ->  No change in network (IE, HGL, etc.)

3)  Import .STM into design drawing -> Choose to Create a New Network ->  Does not create a new network

I've tried closing C3D, and checking, still no change.