The .Show function on a form accepts 2 values for the type of Display. Those values are 0 and 1. 0 would, in essence vbModaless which doesn't technically exist as a Visual Basic Constant. And 1 is vbModal (showing ontop of all other windows.
Now when showing a window from a plugin you have to use vbModal if you choose to show a window using Formname.show. On the other hand if you use the Windows API as shown in the post i made awhile ago you can do it differently.
Matty's reply to Showing Form without vbModal in VB? For the programmers out there...