Comment 9 for bug 782464

The dialog looks like this effectively:

<Website Name>
<speed dial, toolbar, folder1, folder2, folder3>
[x] Run as web app
[Cancel] [Add]

The combo box lets you choose between the speed dial, the toolbar and a folder. Despite technical details these can be seen as exclusive options to the user. If you need more than one of them, open the dialog again. I think this is actually a corner case.