AutoCAD Raster Design

[#1]

I am working on a combination raster / dwg file.  I have modified raster / dwg combo files numerous times in the past without issues.

I am resizing the raster image (.tif) to fit into my company's 36x24 standard title block and need to move some things around to get this busy raster to fit into the title block.  As I am trying to clean up the raster a bit (getting rid of specks, unnecessary data that I am redoing in CAD, etc) using the "irubrect" command, inevitably the raster file becomes corrupted.  It always happens in nearly the same manner where portions of the raster appear to have been copied and overlayed on top of each other (see attachments, G is the original and H is the corrupted version after I have tried to work on it).

I don't believe I have ever had this problem before.  I have tried using a previous rev of the raster file (no changes had been made between rev F and rev G), but the same thing happens with the previous rev of the raster.  I have also tried inserting the raster into a different dwg file to see if it is a problem with something being corrupt in the dwg causing the raster to get screwed up.  It doesn't matter which dwg I try to overlay the raster on, it always gets corrupted in the same manner.  I have also tried just opening up a new dwg (acad template), inserting the raster, and editting similarly with "irubrect" - this also eventually results in corruption to the raster.

So it seems like my raster must be corrupt somehow???  Has anyone experienced a similar problem and how did you resolve it?

Thanks for any help you can offer.

Tom

[#2]

BTW - I am running AutoCad and Raster Design 2011, if this is pertinent at all.

Tom