Comment 31 for bug 562423

You can also issue a 'killall gnome-keyring-daemon' from the command line if you are ssh'ing in from a terminal first or using putty.
You can then bring up the desktop with vnc.
Full description from windows machine:
Open putty and connect.
Open vncviewer and connect.
Issue 'killall gnome-keyring-daemon' in putty vncviewer password prompt pops up
Enter vnc password.
You may have to issue another 'killall gnome-keyring-daemon' to get the desktop to show. Sometimes you do, sometimes you don't.
This worked everytime for me.

Hope this helps