Please describe the problem:
I'm using the Quodlibet music player, and when I updated to libgstreamer0.10
0.10.3 from 0.10.2 yesterday, the UI started to hang for up to 5 seconds when
changing the song, seeking, or pausing/unpausing, while the music continued playing.
I don't have any other apps which use GStreamer 0.10, but I was able to fix the
problem by downgrading to 0.10.2, so it looks like it's definetely a problem
with GStreamer.
The problem happens both using alsasink and osssink.

Steps to reproduce:
1. Install libgstreamer version 0.10.3 and the latest version of Quodlibet, or
probably any other music player using GStreamer 0.10
2. Change the song, seek, pause/unpause

Actual results:
When changing songs: The UI hangs and the old song continues playing for upto 5
seconds, then the next song starts and the UI is responding again.

Expected results:
The next song should start immediately (or in a reasonable time)

Does this happen every time?
The delay varies between 1 to 7-8 seconds, but most of the time (I'd say 95%)
it's around 5 seconds.

Other information:
I'm using Debian sid with mostly up-to-date versions of all packages.
Here are the version of gstreamer-relevant packages:

libgstreamer0.10-0              0.10.3-1
libgstreamer-plugins-base0.10-0 0.10.2-2
gstreamer0.10-plugins-base      0.10.2-2
gstreamer0.10-plugins-base-apps 0.10.2-2
gstreamer0.10-plugins-good      0.10.1-2
gstreamer0.10-plugins-ugly      0.10.1-1
gstreamer0.10-alsa              0.10.2-2

Could it be an incompatibility between the 0.10.3 libgstreamer and the 0.10.2
plugins?