X1=>X3 Browser Issue

While exploring my newly installed X3cP, I notice that some (all midi, test) projects prepared in X1 opened in X3 contain a non-functional browser.  On first opening, there's no browser window, open or closed (even when the file was saved in X1 with the browser showing open).  Hitting "B" opens the window, but it's totally unresponsive to the mouse.  The only thing I can do is toggle it open or closed with the "B" key.  (If I open it in X1, the browser behaves normally.  For other X1 projects which contain at least one audio track, the browser behaves normally when they're opened in X3. ) 
 
Is this a known issue?  Am I missing a simple setting?
 
Thx, Ron