Create Window Mac Issue

On windows I have been CreateWindow with a style of 0. Not quite sure where I found out that I could use a style of 0 but this gives me the desired window effect. However when I use this on a MAC if I create a canvas using this window as the parent the following exception is thrown

2006-03-14 00:14:12.425 .CreateCanvas[763] *** -[NSNextStepFrame contentAlpha]: selector not recognized
2006-03-14 00:14:12.426 .CreateCanvas[763] Exception raised during posting of notification.  Ignored.  exception: *** -[NSNextStepFrame contentAlpha]: selector not recognized

Have I dreamt the style of 0 or is there a specific issue using this style on the MAC?

Okay I have tracked this down a bit further. It seems to happen if I create a window without the titlebar and then assign a canvas to it. It works fine on a windows machine - just falls over on the mac. Is there some restriction about creating windows with titlebars on the mac that anyone knows about?

I did a bit of googling and didn't find much. The fact NSNextStepFrame is an undocumented internal type makes me think this may not be easy that easy to fix.

Yep this link seemed the most similar issue I could find.

http://lists.apple.com/archives/Cocoa-dev/2002/Nov/msg01167.html

Not very encouraging though. Methinks it may be time for plan B ;)

Do panels suffer the same problem? If not have you tried parenting the canvas to a panel on the titleless window?

no - do you think that might make a difference then? I can give it a go anyway and see