Disappearing Surfaces

[Anonymous]

Hey All, 
We use Land Development Desktop 2004 in our office and lately we will create a surface using points that were imported from surveying only to find out later the surface is gone. It has happened in multiple projects. After the surface is created it shows up in the Terrain Model Explorer and some how/some way it seemingly vanishes into thin air. It has been different every time so I cannot find a common factor as to why they are disappearing. If it helps most computers in the office are XP and my own has windows 7, and no we are not using Novell (i know there were problems with people re-naming surfaces and they would disappear when Novell was being used) Has ANYBODY else had this happening to them and how in gods name did you fix it?

As a side note, the surfaces are actually disappearing from the "dtm" folder in the project as well.  Also we currently have service pack 1 installed.