>You mean a custom object just sitting there? That shouldn't cause a problem in itself. Almost all my forms have one or two of those sitting on it. Does this object create another controls and store the object reference? Did you make references to the object itself somewhere else? Just to see whats up, would you mind posting the code for that object?

It's a whacking big object, code-wise, so posting it is kind of out of the question. But yes, it was just sitting on the form. It does create other child objects, which I made sure were destroyed before the form itself was destroyed. I even tried manually issuing a WhackingBigObject.Destroy call in the Form.Destroy to no avail.

Adding a custom control visually should be perfectly legal, but there sure was something locking the form to the class (or vice versa)...