Comment 2 for bug 462624

This happens because Subversion is unable to connect to gnome keyring
when you log in remotely. If Subversion cannot connect to gnome keyring,
it falls back to storing passwords in plaintext (and asking you before doing so).
So this is not a bug since the software is working as expected.

To use the gnome keyring password store when logged in from remote,
you could start a new gnome-keyring-daemon in your remote login session.
Or try to connect to an already running gnome-keyring-daemon somehow,
this might also be possible (though I don't know how).