MacOSLib elements running out of bounds when resizing

Happy new year to all of you, and for another one full of newbie questions:

I am currently developing a small desktop app for Macintosh on which I use the cocoa.NSSearchfield element which is placed on a rectangle. Nothing spectacular, although I had some window resizing problems first – some of the elements placed on the rectangle didn’t redraw correctly upon resize, but I could handle this by some invalidate and/or redrawrectangle calls.

The whole rectangle can be made invisible by clicking on a button which cuts the height of the window appropriately. Once I hide the lower window portion and make it visible again, the NSSearchfield may not get drawn, no matter how I try to refresh it. Sometimes it is shown, but once I resize the window manually its top position seems to be influenced and it wanders of its parent. Other elements like a segmented control with system icons will be redrawn correctly, at least after I resize the window for another time. The searchfield will not reappear until I close and open the window again. Manually overriding its Top and Left positions with the defaults won’t help, so I wonder if this is due to an own construction mistake or a bug of some MacOSLib elements – NSTableview behaves the same.

I thought this could be initiated by some sort of animation toolbox interference, but it stays with this behavior even when I set the window boundaries manually without animation.

I can send you a small quicktime movie showing this behavior. As some of my address book entries are shown (although only names), I would rather not post it officially, so drop me a PM if you are interested.

Any advices from you would be highly appreciated.

Ok, it’s not MacOSLib elements, it was the round rectangle I used to connect window elements optically. When this was resized, some of the contained elements ran out of bounds, as it seems because their top positions get wrong. I removed the rectangle and everything’s fine now.
Although – still wondering if this is an GUI problem or a Xojo caused one.