Okay, in wondering if the problem I have is specific to my system, here's a little something to try. MAKE SURE YOU HAVE YOUR DRAWING SAVED!
MSCAD 2008 SP1.1
Using either the text editor or even notepad or any program for that matter, copy a string of text that begins with at least two spaces. When at the command prompt, hit Ctrl+V (standard paste shortcut) and see what happens.
My program goes absolutely squirrelly and the only way to get it back to normal is through luck. Restart the program and all is normal. Sometimes comes back just from doing a fast zoom in/out with the scroll wheel. I want to know if my 'puter is the problem or if this is with MSCAD..... so who's ready to be a guinea pig?