xfce4-screenshooter doesn't seem to remember the zimagez password. I'm not sure if this was deliberate or not. If it was, caching the password in the user's keyring shouldn't be an issue. The login name, however, is cached. I was using version 1.8.0.
Same here, version 1.8.1-2ubuntu1 Bump.
Closing this bug since Zimagez is no more, I removed support to it (in master, to be released). For more details, see bug #14283.