AutoCAD 2010/2011/2012 DWG Format

[#1]

I am using Autocad 2010. I have been using 2008, but recently upgraded. I have a project that one particular file is driving me nuts! I can not use trim or extend on any existing line work. However, if I draw two non intersecting/crossing lines and ust the 'TR' command it works fine. I have checked to see if all lines are in the same plane and the appear to be. The only way I can trim or extend is if I use the 'Flatten' command. Can anyone help with this issue? 

[#2]

Are they co-plannar?

When they are non-coplannar no trimming or Extending will work.

[#3]

I have checked and I am not sure. How can I be sure that all lines are coplanar? Some lines will trim and extend just fine, especially if I draw a new line or pline. Berlin Architects 275 Veronica Lane PO Box 4119 Jackson, WY 83001 T.307.733.5697 F.307.733.5761

[#4]

Attach part of that drawing where the problem is, let's see why.

[#5]

So this is a section out of the drawing I am having problems with. I simply selected this drawing, cut/paste, and saved it under trimextendissue. I clouded two lines that I attempted to extend to. Christopher Berlin Architects 275 Veronica Lane PO Box 4119 Jackson, WY 83001 T.307.733.5697 F.307.733.5761

[#6]

Can you try again, no attachment yet.

[#7]

Hmm trying again Berlin Architects 275 Veronica Lane PO Box 4119 Jackson, WY 83001 T.307.733.5697 F.307.733.5761