I finally assigned fot the default unit in the details section of my Purchase Order form based on the lookup value of my Item combo box. Now everytime I open my form, it flickers.

What do I do to stop the flickering? Thanks all.

Do you have the timer set to anything or have any evemt on the Timer event? If so, this can cause flickering as it refreshes the form on the timer event.

Yep, you may well have your query on a loop, so its permantly working away and causing the flicker. Try to edit your code to it only does this once or just on the opening of the form, and not on Current / Active