Using

gst-launch-0.10 v4l2src device=/dev/video1 use-fixed-fps=false ! video/x-raw-yuv,format=\(fourcc\)UYVY,width=320,height=240 ! ffmpegcolorspace ! ximagesink

I'm getting

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
ERROR: from element /pipeline0/xvimagesink0: Failed to create output image buffer of 640x480 pixels
Additional debug info:
xvimagesink.c(1992): gst_xvimagesink_show_frame (): /pipeline0/xvimagesink0:
XServer allocated buffer size did not match input buffer
Execution ended after 144560000 ns.
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
FREEING pipeline ...