* When re-populating grdUnapproved, suspend all layout tasks to try and save a few thousand events being fired
* Modify code to remove group colums from grdUnapproved - it wasn't working properly before.  (Seems fine now)
* CellFormatting event occasionally seems to fire with some really dumb (= invalid) arguments (RowIndex/ColumnIndex < 0)  Return from event immediately if we get invalid values.