I can't get certain hidden lines to show up when RMB -> Show/Hide -> Show Hidden Edges.

I have a section view in HLR and I want to show some tubing underneath a plate. The tube in the upper right and sometimes upper left shows up, but the lower two tubes are not visible. However I can select their edges and with Dynamic Highlighting active they become orange when I hover over them.

The picture attached "Hidden Lines Removed" shows my problem. "Hidden Lines Visible" will give you a better idea of what exactly I want to show up, but without all the clutter.

Has anyone else encountered this type of problem? Is there a simple fix or is this a deeper bug? Any help would be appreciated since I've been trying every little trick I know for the last couple hours including a good old fashioned restart, graphics driver update, and I've scoured the forums. I guess if it comes down to it I can just selectively hide all the edges in HLV or sketch convert entities...

Thanks in advance!

I'm working with Solidworks 2012 SP5.0