A vba code command does not execute as it should...

I have a large vba-based Excel workbook application that I'm developing and I occasionally have a need to update the screens during execution, and other times not update the screens.

I'm using the:

Application.ScreenUpdating = True

or

Application.ScreenUpdating = False

as needed.

I have one routine that, when I want no updating of the screens during a particular execution of some code the code command is ignored and the screens update.

If I step through my code (F8) and execute the

Application.ScreenUpdating = False

statement, then hold my mouse over the line of code, the tool tip indicates that screen updating is still set to true.

If I then type the command in the Immediate window, the tool tip now indicates that the screen updating is set to false. Yet when I press the F5 key to execute the remainder of the code...the screens are updating. There is no instance of the code command that sets the screens to updating = true so I have no idea why the screen updating continues to execute as if set to True.

Anyone have any ideas?

I'm using Excel 97 (XP, SP2) and Excel 2007 (Vista).

Thank you,

Stu