Comment 2 for bug 769820

I think the problem here is that of packaging, something is broken in the way akonadi-googledata and libgcal is packaged on Kubuntu Natty. I recompiled both pacakges from source doing the following

first remove your current akonadi gcal resource entry (if you still have one)
in the akonadi system settings module. then open a konsole and:

~$ sudo apt-get install build-essential linux-headers-$(uname -r)
~$ mkdir builds
~$ cd builds
~/builds$ apt-get source libgcal
~/builds$ sudo apt-get build-dep libgcal
~/builds$ apt-get source akonadi-googledata
~/builds$ sudo apt-get build-dep akonadi-googledata
~/builds$ cd libgcal-0.9.6
~/builds/libgcal-0.9.6$ ./configure
~/builds/libgcal-0.9.6$ make
~/builds/libgcal-0.9.6$ sudo make install
~/builds/libgcal-0.9.6$ cd ..
~/builds$ cd akonadi-googledata-1.2.0
~/builds/akonadi-googledata-1.2.0$ mkdir builds
~/builds/akonadi-googledata-1.2.0$ cd builds
~/builds/akonadi-googledata-1.2.0/builds$ cmake ..
~/builds/akonadi-googledata-1.2.0/builds$ make
~/builds/akonadi-googledata-1.2.0/builds$ sudo make install

and when I rebooted the invalid password issue were gone and syncing is possible again. I could see my google contacts in kaddressbook and my google calendars in korganiser. the guide I followed was based on this bug report http://bugs.kde.org/show_bug.cgi?id=264861#c27 and this comment http://bugs.kde.org/show_bug.cgi?id=264861#c26