David,
Yes, if you had private DS then it'd be impossible for them to stomp on each other. But if they are in the same DS anytime the form with the grid gets focus when the grid has focus it will select back to the grid alias. I think you can use the alias() test to pull focus away from the grid and set a flag to let you re-set focus there on Activate().
>All in the default datasession. This is an ex 2.6 app. I can see what you are getting at. I think if I was running private datasessions there wouldn't be an issue at all.