I use PI XL - yes I have had this happen - usually if I just wait a while - maybe 5 minutes or so - I know it seems like hours!! LOL - it will correct itself. What I sometimes do is save everything and then close the file and re-open - strange I know but it does seem to help. Don't know what else I can suggest - just to make sure you have the mose recent patches for everything. I recently upgraded to more RAM - 768 - this helped tremendously too!!
Holly
