blank row in datagrid

ActionScript returns systematically a blank row when displaying a datagrid, which is kind of annoying...

When I searched in Google for this issue, I could find plenty of posts, on stackoverflow.com, http://www.actionscript.org/, but none were satisfactory - solutions look more like hacks than fixes in my opinion.

So digging a bit in the documentation, I found a useful attribute for DataGrid:
lockedRowCount

Set it to the number of rows you need to display, et voila!