*** vb.net - help debugging drag'n'drop problem ***

I have a vb.net project (VS2012) that has a main form with a grid control on it. I have implemented drag n drop so I can drop files and eMails onto the grid. This causes another form to load where notes can be added. The user then clicks a Save button on this second form which closes it, returning focus to the main form which then runs the code in the main forms Activated event which refreshes the grid. This works great if I drag files from the desktop, but if I drag files from another application (Win Explorer, Outlook), the drop event fires fine and the second form loads but after the user Saves and the second form closes, the Activated event on the main form doesn't fire until they click on the main form. Help appreciated !