I'm passing a data table to a form.  This table is then bound to a binding
source which is in turn bound to a datagridview so that only a subset of the
table is ever displayed (filters by key).  This form is your basic dialog
with OK/Cancel buttons.

For reasons too complicated to explain, what I need to do is be able to pass
this same data table multiple times to this same form, make multiple
adds/mods to the table (for a given key) and then either accept or reject
each batch of adds/mods.  All of this is to take place without updates to the
database.  The update is supposed to happen only once much later on.

When I simply try to loop through the datatable and removing unwanted new
rows, I get RowNotInTableException errors (This row has been removed from a
table and does not have any data. etc...)

What would be a good approach to this problem?  Anything I'm missing?  (This
feels like deja vu.)