i'm back to the 2.6.17-1.2187_FC5 kernel now
all it took was rebooting, failing the x-server login, but the 'automatic' process (requiring my root p/w at commandline) restarted the x-server upon 'trying' w/ a new config.
once the x-server started, i was prompted w/ a GNOME-ish display-settings screen, into which i plugged 1280x1024 (up from 1024x768) and from 'thousands' of colors, i bumped it up to millions.
but, it didn't boot into KDE as such. i can't seem to get my 1280x1024 resolution back. it's not showing up in the KDE display config (in the 'Control Center').