[flexcoders] How do I set the text color of a row in a datagrid (without memory problems)?

[fidelityphil]

I need to change the text color of a given row of a datagrid if one of 
the columns has a value.  I put in an instream itemRenderer on the 
datagrid (above the columns definition) which works fine.  However, if 
I then try to sort one of the columns by clicking on the header, the 
titles disappear from the column headers and the application locks up.  
How do I prevent the latter from happening on a column sort?