I can't duplicate this behavior on my windows machine, so I'm assuming you've found a bug. When I get access to my mac I'll check it on there as well to confirm.
Does seem to be a bug. I note that any attempt to resize the window immeditately re-hides the status area.
Also the status area is only partly revealed. The section containing the layout dropdown doesn't show.
I posted this in the bug report section and it was already officially accepted as a bug on Mac OS X only.