I have a reoccurring problem; excel suddenly and in an uncontrolled fashion reverts a spreadsheet to a point where I was several minutes or hours ago. It seems to happen when I am do a copy/paste. Sometimes when I do a copy/paste the sheet suddenly “flashes” and I am back to where I was at some point earlier in the day. It is unpredictable, and so far unrecoverable. I compensate by saving often. When the “flash” happens I usually just close without saving and reopen the last saved version. I sometimes get the warning that there is a lot of information on the clip board. I was wondering if the two were related. Am I somehow loading too much information on to the clipboard and “crashing” the spreadsheet?? The last time the “flash” happened I was able to see the spreadsheet undo some of the work I had done, usually it happens too fast to see any changes but this last time I actually saw it reverting.