Weird window behaviour in all versions of Mozilla

I haven't been able to find a refence to this in the text on the Mozilla
web site, but has anyone else seen this bug?

Start a download from a browser window, I use the download dialogue
setting, then close the main browser window, leaving the download
dialogue on its own.

Now try to access any of the menus, or open a new window. You can't!

But, minimise the download dialogue to the Dock, and you can access the
menus again.

-- 
Andy Hewitt **  FAF#1, (Ex-OSOS#5) - FJ1200 ABS
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