Improve spark List performance

[Federico De Maddalena]

Hi! I'm working on a mobile project.
I created a spark List, which item renderer is an extension of
ItemRenderer. Each of my item renderer contains one spark Image, one
Label and a number of small buttons which varies from 3 to 20.
Now, scrolling the list is terribly slow. There are ways to improve
scroll speed? I spent a lot of time but without success.
Regards
federico