Sorry, but it didn't really help me...There doesn't seem to be anything going on that would modify the drawing in any way....
So, you're saying that if you start AutoCAD, then close Drawing1 as soon as AutoCAD is finished loading, you are asked if you want to save the changes? That's very odd! When my AutoCAD loads, I have a few lisp routines load and even RUN with every drawing and it doesn't ask me if I want to save.
Your REVCLOUD lisp, how is it loaded? Is it in your startup suite or did you put it in your acad2000doc.lsp? Just curious.
I think I'm out of ideas. I know it doesn't take long for that to happen...