>Barry, are you getting bitten by the fact that a toolbar doesn't get focus, so if you typed a value into the textbox you're sitting in when you hit the toolbar button, that value isn't saved?

Garrett, don't think so, I can tab between my textboxes before closing and the same thing happens. As suggested by Cetin, I've now changed it to manipulate the parent's property directly so problem solved (for this time).
Thanks for the idea.