Window memory leak? And if – on Mac OS X only?

I recently stumbled upon feedback #34956 by Frank Pohling who claims that on OS X, a window being closed would cause a memory leak of about 1 MB each time. I tried this on one of my projects where I use a lot of changing windows, even with transformations being illustrated by a scaling/flying rectangle which is basically another window and it seems to me he is right: Each time I close a window a big chunk of memory is not being released.
He has attached a demo project to his Feedback entry and I manipulated this to open/close windows in an endless loop, being able to crash Xojo in about a minute each time when the 4 GB barrier is being taken.
Therefore: Could you verify if this is indeed a memory leak? And if: Does it exist on Mac OS X only or is this happening on each platform?
(Sure, you could say one shouldn‘t instantiate that many windows. But shouldn‘t the memory be released in time anyway? Or is this some coding problem instead?)

Yes, it does increase the memory each time by 1 MB and doesn’t release it. Interestingly this doesn’t happen with RB 2012 v2.1 (Cocoa), where it is only an increase of 1/20 MB.