OK, I verified that I do not have Calculation=xlManual.
ErrMsgOvrrdeFlg is just a boolean cell that I manually change when I don't want error messages etc. to display when I want to print the sheet. I use it about once a week,
and I have a button that tells me what it's current state is at all times. Wait a minute ... maybe that is the problem. I'm not sure why opening/closing the conditional formatting dialog box would change its effect, however. I'll follow up on that. Thanx for the suggestion.