[flexcoders] variable row height with item renderer

[mt1_18]

I am using a textArea item renderer because I need to change the
background color of the cell.  However, the text in the textArea is
more than the height of the row and I am getting scrollbars on the
textArea component even though i am using variableRowHeight=true. 
When I remove the item renderer the row height changes so that there
is no scrollbar in the cell.  How can I have the entire contents of
the cell be displayed w/o scrollbars and at the same time change the
background color of the cell.  I hope the question is clear

Thanks