>Rob gave the answer but you *might* get by just by checking the Remove() return value. This will be false if the item was not found - but also false if the Remove() failed for some other reason (which is the possible downside)

In my case, this was generating an error yesterday. This is why I had to adjust.

But, what I do not understand is why we can assign a primary key when adding an item but cannot use it when removing it. We can only use the 1-based incremental value for removing an item.