cairo.Error: invalid matrix (not invertible)

[Justin J Stark]

When I start kungfu with a DVD in (or start kungfu and then insert a DVD),

justinjstark@melmac:~$ kungfu
INFO kf_state Loading state from /home/justinjstark/.config/kungfu/state.pickled
INFO kf_gst Using dvdreadsrc element
INFO kf_dbus Adding volume: /org/freedesktop/Hal/devices/volume_label_LORD_OF_WAR
/usr/lib/pymodules/python2.6/KungFu/kf_gtk.py:870: GtkWarning: gtk_range_set_range: assertion `min < max' failed
  self._scale.set_range(0.0, dur)
INFO kf_gst Reading titles from LORD_OF_WAR at /dev/sr0
libdvdread: Using libdvdcss version 1.2.10 for DVD access

libdvdread: Attempting to retrieve all CSS keys
libdvdread: This can take a _long_ time, please be patient

libdvdread: Get key for /VIDEO_TS/VIDEO_TS.VOB at 0x00000148
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_01_0.VOB at 0x000001bf
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_01_1.VOB at 0x0001cb3a
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_02_0.VOB at 0x003c47f4
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_02_1.VOB at 0x003c482d
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_03_0.VOB at 0x003c7d04
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_03_1.VOB at 0x003c7d3d
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_04_0.VOB at 0x003c8125
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_04_1.VOB at 0x003c815e
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_05_0.VOB at 0x003c9076
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_05_1.VOB at 0x003c90af
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_06_0.VOB at 0x003c9fc7
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_06_1.VOB at 0x003ca000
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_07_0.VOB at 0x003cc5e8
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_07_1.VOB at 0x003cc621
libdvdread: Elapsed time 0
libdvdread: Found 7 VTS's
libdvdread: Elapsed time 0
INFO kf_gst 7 titles found on LORD_OF_WAR
INFO kf_gst Title 1 has duration 121:40
Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/KungFu/kf_gst.py", line 364, in _on_preroll_handoff
    ctx.scale(sx, sy)
cairo.Error: invalid matrix (not invertible)