I couldn't open any bookmark. They were listed, but clicking on any bookmak didn't have any effect. The only option that worked was "open in new tab".
I enabled the Docs & Spreadsheets integration, but when I clicked on a doc/xls file, I got a message that said: "Firefox is already running but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." I tried restarting Firefox and the PC, but still nothing.
I reported the bugs to Google and here is the answer (partially edited):
Thank you for your note. We're sorry you're still having trouble using the Docs and Spreadsheets feature of Google Toolbar for Firefox. Many of our users report this. Please try the steps below:
1. Uninstall the Toolbar.
2. Open Firefox's "Tools" menu and then select "Add-ons."
3. Disable all the extensions in your "Add-ons" screen.
4. Restart your browser, then reinstall the Toolbar from http://toolbar.google.com.
5. If you're able to use the Docs and Spreadsheets feature, please enable your extensions, one by one, until you find the conflicting add-on. Please let us know which add-on caused the conflict.
Please let us know whether this resolves the problem.
I don't think this a good solution, as disabling all extensions and enabling them one by one is time consuming. But I tried to follow at least the first advice: uninstalling the toolbar. I clicked on "Uninstall", restarted the browser, only to see that the toolbar is still there. After restarting the browser, I got the intro dialog that asks you if you want to enable PageRank and other options.