gstreamer chooses wrong resolution with gspca_zc3xx webcam?

Binary package hint: empathy

After the move to Intrepid I was unable to videoconference through empathy. My local video simply wouldn't show up. Once the v4l2 stuff settled down other video programs (cheese, ekiga, skype) began working again, but empathy never caught up.

I ran STREAM_ENGINE_PERSIST to get telepathy-stream-engine debug output, and here's the error message:

   ** (telepathy-stream-engine:5966): DEBUG: bus_async_handler: got error from v4l2src1: Device '/dev/video0' cannot capture at 352x288: v4l2src_calls.c(1298): gst_v4l2src_set_capture (): /GstPipeline:pipeline0/GstGConfVideoSrc:gconfvideosrc0/GstBin:bin2/GstV4l2Src:v4l2src1:
   Tried to capture at 352x288, but device returned size 320x240 (1111 13), destroying video pipeline
   ** (telepathy-stream-engine:5966): DEBUG: Closing all video streams
   libv4l2: error converting / decoding frame data: v4l-convert: error destination buffer too small

Note that it tried to capture in CIF but go the nearby VGA mode... as if some player was confused about which resolution to request or which was requested.

This bug is very similar to their reported bug at http://bugs.freedesktop.org/show_bug.cgi?id=18901 . There Oliver says it's either a problem with gstreamer or the kernel driver. Lovely.

I ran cheese with its verbose logging and after it got on its feet it showed the following line in terminal:
v4l2src name=video_source device=/dev/video0 ! capsfilter name=capsfilter caps=video/x-raw-rgb,width=640,height=480,framerate=30/1;video/x-raw-yuv,width=640,height=480,framerate=30/1 ! identity

So cheese seems to properly detect available camera modes and requests one explicitly? I typed this line into gstreamer-properties as a custom video source and empathy video began working fine.

With so many players, from empathy to stream-engine to gstreamer to driver, I have no idea where the actual fault is. It looks like some autodetect code is failing to choose an available resolution so I would guess gstreamer.

Anyway, webcam:
Bus 001 Device 002: ID 0ac8:303b Z-Star Microelectronics Corp. ZC0303 WebCam
telepathy-stream-engine 0.5.3-1
empathy 2.25.2-2ubuntu1~ppa8.10+1
And I will attach the debug log from telepathy-stream-engine