I believe that SW files have the graphics data saved within them so that they seem to open quickly. That is what you see when your drawing looks like it did when you saved it last. If your drawing needs to reflect the changes, then you need to go back into the drawing and correct all of the stuff that broke. I don't see any way around it. If you would rather just give up on the changes, you might be able to reload the original from your PDM or a backup.