Please describe the problem:
While receiving a RTSP/RTP stream, if the stream is sought the video stream is shown properly, while there is no sound for a while (~3 seconds). Then the buffered audio starts playing at double(?) speed till it synchronizes with the video, which has been played smoothly all the time.

It can be depicted like this:

Video        Audio

00:00         00:00
-(playing)      - (playing)
-               -
-               -
-               -
00:23        00:23
(seek)       (seek)
01:20        (silence)
- (seamless) (silence)
-            (silence)
01:23        01:20 (not synchronized)
-                 = (x2)
-                 = (x2)
01:26        01:26 (synchronized)
-                 -
-                 -
-                 -
...               ... 

At the time of seeking (PLAY RTSP message with the proper 'ntp' parameter sent and Reply received), at the client side this message is prompted:

GStreamer-CRITICAL **: gst_clock_set_calibration: assertion `internal <= gst_clock_get_internal_time (clock)' failed.

Seeking the same content in a local environment works with no issues.

Steps to reproduce:
1. Set up a RTSP server (tested with VLC 0.9.4) with a VoD content.
2. Start playing the content with gstreamer.
3. Seek to any point in time of the streamed media.


Actual results:
Video is gapless but audio remains silently buffering, then plays at double speed till it synchronizes with the video and then both audio and video continue the playback properly.

Expected results:
Both the video and audio jump to the asked position in a synchronized way.

Does this happen every time?
NEARLY every time i tried (9 out of 10).

Other information:
I've been told that this bug has already been reported but I couldn't find it, so I file it just in case.