Some lines disappear when converting to editable poly

[ieo]

I am quite new to Studio Max , so I have a problem with some basic tools.

I am currently working on a model where I am connecting 12 different abstract sections. I have already managed to convert some of the lines into editable polygons and worked fine with them, but now I am stuck because a lot of the lines disappear when i convert them to editable polygons. So how can it be that these continuous lines disappear?

Any help is appreciated!

And I am working the 2010 version in windows 7 if it makes any difference..

[ieo]

ok, I solved my problem by extruding the line and then converting the shape to an editable poly, capping the original line and deleting the extruded line.

Hopefully this will be useful for someone else.