Yes, using Firefox, you can see your Picasa Web albums. You should see these albums using any other browser from your computer. Also, you need to know that Picasa doesn't provide any specific plugin for Firefox. For this reason, using your browser, you can open only the photos stored on your online account. If you have issues, press Ctrl + Shift + Delete key combination to clear all cache, cookies and temporary Internet file and update the browser to the latest version. Check the official Support page for further information.