It should be a logical mistake.
For every row you delete, you should decrease the index count.
For e.g
If you want to delete rows 1,3 and 6 from a table which contain 6 rows
delete row1 as Table.Row[0].instanceManager.removeInstance(); [now the row count will become 5]
delete row3 as Table.Row[1].instanceManager.removeInstance(); [note that index is 1 because you already deleted one record, and index starts from 0]
delete row6 as Table.Row[3].instanceManager.removeinstance(); [already two record deleted, so 6-2-1= 3 is your index to delete]
Do you understand the logic?
Nith