Did you noticed that Opera have small problems working with Gmail? If yes, there's a script that was made to make the compatibility of Opera and Gmail better.

First, you should go to http://code.google.com/p/gmail2-for-opera/ and download this java script - gmail_2.0_20080410.js (name might be different, because of different version). I prefer to save this script to ~/.opera/ . After this open Opera and point your browser to your gmail account - https://mail.google.com/mail/#inbox. After page is loaded click right button on any free space on this page, from the context menu select "Edit Site Preferences...", then click on tab "Scripting", and "Choose" that file you have just downloaded. That's it.

Unfortunately this script doesn't help neither with Picasa, nor Notebook.