Mac: Modal sheets lose their transparency on 2nd open

Platform:

Mac OS X

Platform details:

os x 10.5.4, mac pro 2X 2.66ghz, 7 gb ram safari 3.x

Compilers:

GCC

Compiler details:

generic x code compile

Steps to reproduce / test case:

In your demo file: /usr/local/Trolltech/Qt-4.6.0/examples/widgets/windowflags

1. Launch app
2. click the "sheet" radio button and watch the sheet open (notice the slight (and correct) transparency showing item that resides behind the sheet)
3. Close the sheet but clicking on the close button
4. Press the sheet button again to show the modal sheet again.

BUG: notice the transparency is lost now, it only works the first time and you must quit the app to see the transparency again.