I am just not seeing the problem you describe. I imported the project and ran it; Scrolled 20+ times up and down, both with the arrows and clicking in the scroll bar. Also tried partial scrolls up and down (ie. not all the way up nor all the way down). The numbers in the combo-boxes drop-downs always match the displayed number.
Perhaps this is not a problem in your code but something in your development system. I am using the following: Flex Builder Version 3.0 (Build 3.0.2.214193) Flex SDK 3.5a (Build 3.5.0.12683) Flash Player WIN 10,0,32,18 Debug Firefox 3.5.7
