Excel VBA screen updating

Hi,

I am having some trouble with the screen update command. As recommended by the trainer, I used application.screenupdating = false at the beginning of my macro, but it still updates the spreadsheet and is really annoying for any end-user. I have lot of iterations happening within my macro. Any reason why this is happening? I don't select or activate within the macro, which means i don't use the clipboard. Not sure where the mistake is. Please do look into this. Thanks.