Pipe Network in Multiple Sections

[ccookusi]

Civil 3D 2012 - SP1

I have a drawing that has 146 Sections views in it.

The sections show existing ground surface and corridor (Road Project).

It takes about 15 seconds to open the drawing (Not Bad).

I now need to show the storm structures/pipes.

Reference in the pipe network, show it in each section.

Once this is done and saved, the drawing now takes 17-18 MINUTES to open!

In summary:

Without the pipe network source shown it takes about 15 seconds to open

With the pipe network source shown it takes about 17-18 minutes to open.

Is there a known issue with slow load times with a pipe network shown in multiple sections?

I have had this issue since the 2010 release.

Autodesk....Please Help!