Hello Wayne,
I found how to reproduce the bug
Open a mb1 project. If you have a button on the form, click right to open the properties of this button.
When the properties window is opened, click on the right to enlarge it (very large on your screen)
Close your project and re-opening
the properties windows is on the left of my screen, and I cannot drag & drop it.
But the properties button works fine to restablish it on the screen
Just the bug of drag & drop
Hope this helps