We are noticing an odd behavior with Application.ScreenUpdating in Excel 2013 as it pertains to multiple workbook scenarios.
With Application.ScreenUpdating = False, performing actions on other non-active workbooks causes Excel to "focus" the target workbook resulting in a momentary screen flash.
For example, if Book1 is active and we attempt to set visibility on Sheet1 of Book2, the screen will flash as Book2 is focused and the visibility method executed. Afterwards, focus is returned to Book1.
This happens on other operations as well - such as protect, unprotect, etc.
It appears to us, that with the introduction of SDI in Excel 2013, ScreenUpdating is not completely disabling all screen updates as it has with previous Excel releases.
Any help would be really appreciated.
Thanks!