Get An error on delete an item using id.

I have a list which contains 30000 thousand items

Now i want to delete an item from the list using id of the item.

Now i am using :

SPlistitem oitem=list.getitembyid(id);

oitem.delete();

Although it deletes an item from the list but throws an error saying "Item does nto exist . item may be delted by another user".

Please help me on this..!!!!