UIScrollbar problem

Hello all. Can anyone tell me if it’s better to create a custom scroll bar rather then using the UIScrollbar provided in flash 8? Adding a precompiled UIScrollbar to my movie bumps up size of my movie by 45K and it also slows it down when it’s animated. I created a dynamic text field and dropped that in a MovieClip so i could attach it when a button is pressed. Is it a bad idea to animate a dynamic textbox with a UIScrollbar?
I can provide the .fla file if anyone would like to see what I’m talking about. Any help would be greatly appreciated.