Ed,

> should have added: I closed the window the grid is in, reopened it
> (which recreates everything) and then it deleted just fine.
>
> Ideas? Sometimes my users send me errors similar to this and I have no
> idea on how to track this down.

This sounds like more of an issue of stale pointers.

I would need a simple application with steps to reproduce to know for sure
and provide a solution.

Jason Wharton