When I set http://i1024.photobucket.com/albums/y305/gnomesrule19/Normalsnotcalculatedoutside.jpg?t=1293763738 normals outside, many of the faces are not outside . How does blender decide where or from which direction(s) outside is? I'm asking because when I convert meshes to .3ds format so that I can import them into Blender the faces that are not calculated outside do not appear to exist.

I've had troubles with recalculate normals not working sometimes , you might have to select the faces with the inverted normals and manually flip them.

Hmmm... how do you do that? I hope that is not the same as having to rotate them XD.

To recalculate normals select all the faces in edit mode and hit ctrl+N. To flip them manually select the face/faces and hit W, this will pull up a menu, then select flip normal.

When 3 or more planes are extruded from a single edge, can cause the recalculate normals function to not work like you would expect it to.