There are no big problems with Firefox 3.0 so far, but it should be installed within a new profile! To create an manage new profiles, you have to activate the profile manager by entering the following in the application »Terminal«:

/Applications/Firefox.app/Contents/MacOS/firefox -ProfileManager

Now, the profile manager starts while Firefox starts up.

Add-Ons and themes have to be re-installed, and bookmarks can be imported within the bookmark manager.

So, I got a solid working browser, that I use many hours a day and crashed only twice. But there are some (more or less important) problems:

– The installation mentioned above should work as a standard installation and the user must informed about that while the installation. Otherwise the problems while installing into an existing profile should be fixed as soon as possible.

– The cursor for zooming in and out images does not appear properly since the alpha channel in these TIFFs are some pixels too big. You can fix this by correcting the following images e. g. in Photoshop and then saving them in Preview.app with using the PackBits compression:
Firefox.app › Contents › MacOS › res › cursors › zoomIn.tiff (zoomOut.tiff)
Be carful and try this with a backup fo Firefox, first! Damaged images will cause crashing Firefox!

– The bookmarks and cookies are no longer stored in HTML files but in SQLITE databases. Though bookmarks can be exported and imported as HTML files, my opinion is that the HTML files for both bookmarks and cookies was the better and easier way to manage them manually.

– The extension »PrefBar 4.1.1« causes an application crash when set to appear in the Firefox menu in its preferences.

– The behavior takes getting used to. Perhaps it should be switchable in an easy way. Now, you can only try to manage it in the about:config ( then type »browser.urlbar.*«.)

– Firefox 3 is said to render webpages faster than previous versions. I can't watch this so far.

In summary: Firefox 3.0 is basically good, but it might, should – and I hope it will – be improved soon.