Has anybody ran into this? I have an AutoCAD file done in 2006. I open it in 2007, then save it to a 2000 format.

The file size jumps from a 2mb drawing to a 9mb drawing.

As an experiment I started with a particular drawing and came up with the following:

Original drawing - 3,776kb
Saved as 2000 - 3,775kb
Saved as 2004 - 2,021kb
Saved as 2007 - 2,041kb

Any clues as to what is going on?