Multiple sheets when viewing Inventor drawings in AutoCAD

[8013068]

Our shop sometimes uses AutoCAD to view our Inventor .dwg files. I've noticed that when they open them in AutoCAD, the files sometimes have multiple sheets showing previous versions of the drawings as well as the most up to date version. Does anyone know why this happens, and any way to either stop it from happening, or determine which sheet is the latest version automatically? 

Thanks in advance

[8013068]

For anyone who stumbles across this in the future, I found the answer. Apparently, this can happen from revising the file in AutoCAD.

To fix it, save the file as an .idw in Inventor, then save again as a .dwg. Then it should open in AutoCAD correctly.