The only issue I have seen, is when deleting empty layers, in the Layer Manager. When do these crashes happen to you - are they related to something. or somewhat random?
You could try to Repair the file(s) - you close them, and then instead of Open, go the the Repair dialog.
I usually see overflow messages when I have random entity(s) way off in no-mans land. You can usually check by turning on all layers and doing a zoom extents and see if your drawing zooms WAY out. if so you can try deleting the offending entities, or if you can't find them copy and pasting the good contents of your drawing to a new file leaving behind the wonky stuff.
This would be where I would start but this may not be your issue. Could be an entity with some wacked out geometry that's math is running wild.
Thanks! - Josh Do. Or do not. There is no try. Josh's Digital Downloads is come back online soon. Stay tuned. (soon is a relative term)