Does anyone know of an easy way to reset the Ext.grid.RowNumberer?

Specifically I've got a grid and am using the RowEditor to add a new entry to this (very similar to the RowEditor example: http://dev.sencha.com/deploy/dev/exa...ow-editor.html). When the user presses on cancel, during the edit of a new row, I remove this row from the grid and at this point I'd like to reset the row numbering so that the first entry again becomes number 1 (in the example, cancelling a new item actually leaves the new entry behind, but if you then click on the RemoveEmployee button you'll see that the top entry is now labelled as number 2).

Thanks for any help with this,