Fedora 10 on x61s

Recent Fedora 10 updates destabilized my Thinkpad x61s. (Mouse movement would start getting sluggish and eventually the system would freeze.) It's probably something to do with dri in the xserver (and I don't even know what that means :-) I put this into my ~/.drirc, and my machine has been fine. I think the key is vblank_mode.

<driconf>
    <device screen="0" driver="i965">
        <application name="Default">
            <option name="force_s3tc_enable" value="false" />
            <option name="no_rast" value="false" />
            <option name="fthrottle_mode" value="2" />
            <option name="bo_reuse" value="1" />
            <option name="vblank_mode" value="0" />
            <option name="allow_large_textures" value="2" />
        </application>
    </device>
</driconf>