Black square under Grabbing Hand mouse pointer when on Library

Hello. I’m not sure if mine’s been doing this from the beginning (…I certainly haven’t noticed it until now), but when my mouse pointer turns in to the glove/hand when hovering over Library items (the panel on the very left of the default Pinegrow layout), a black square appears behind the hand, as if the alpha on the mouse pointer graphic were flawed (opaque).

It doesn’t do this for any other mouse pointer or situation that I have found.

It doesn’t appear to be a Windows thing, and changing the mouse pointer theme in Windows doesn’t seem to have any affect.

Also, sometimes, dragging an item from the library to (say) the Heirarchy list (far right panel in the default Pinegrow layout) results in the pointer moving fine, but the Library item SLOWLY following the path the mouse pointer took, drifting across the page until it finally meets up with the mouse pointer.

I wanted to see if this is a known/previously reported issue… and if there’s some known trigger/factor for it.

Win7 Pro 32gigs RAM i7