I've got some more data about two-level SolPart menus not working in Safari and Chrome. I'm using DNN 4.9.0 and Apple Safari 3.1.2 (on the PC) and Google Chrome 0.2.149.30. I see that only when I am logged in as an administrator on my site do the parent items in a menu stop working in Safari and Chrome. If I am logged in as a "normal" user or not logged in at all, the menus work as expected. So there seems to be some interaction between the appearance of the DNN Control Panel and these parent menu items.

Also, just for the record, Safari is available for both the PC and Mac, so it is not just a Mac browser. I find it more convenient to test Safari on the PC along with all the other browsers. I have never found any differences between its behavior on the PC and on my Mac iBook G4.

Finally, I have been using Chrome as my primary browser for over a week without any major problems. When working with DNN 4.9 sites and the web in general, it works quite well. The only time I switch back to IE or Firefox is to use their Developer Toolbars to do debugging. (I also miss the Google Toolbar in Chrome :-))