ADT 2005, loose drawing when using mouse wheel

Hi,

I hope someone maybe able to shed a little light on a problem that is driving me totally mad!

I have a file that when opened at zoom extents and then I try to zoom in with the mouse wheel the drawing changes to a badly pixelated image of squares and thick lines and then will not pan or zoom out, only thing is to close the drawing and then repeat.

Z oom window via the keyboard appears to work, but as soon as the mouse wheel is used the problem starts.

Its an old drawing that I have not generated, but problems seem to have started having bound the drawing a few days ago.

any help gratefully received.

thanks

Have you tried a Purge and Audit first? Maybe there are errors in your file.