Disable handler until code complete.

[sgrya1]

I don't know how to put a title to this.

I made a plugin a for a program that has a Datagridview. Lengthy code runs when selecting cells.

When I click between cells a little faster than the program likes it crashes the program it is plugged into.

I created an invisible modal form to cover the controls and prevent clicks while it is executing but it doesn't seem to work.

Is there anything anyone can suggest? Is the code being broken somehow by a second click or is it added to a command stack?