I am getting an error when I include id3tag in a pipeline using threads. 
The problem seems to occur with all the files I have and it doesn't seem to
matter whether the file has a v1 tag, a v2 tag, or none.   I am using
gstreamer 0.7.6.  This bug might be related to bug 133897, but the pipeline
in that bug report does work for me.  

The command that fails is:
gst-launch-0.8 \{ filesrc location=test4.mp3 \} ! \{ queue ! id3tag ! mad !
audioconvert ! osssink \}
RUNNING pipeline ...
ERROR: from element /pipeline0/thread1/id3tag0: Internal GStreamer error:
seek problem.  File a bug.
Additional debug info:
gstid3tag.c(916): gst_id3_tag_chain: /pipeline0/thread1/id3tag0:
can't seek back to beginning from reading ID3v1 tag

These commands work:
gst-launch-0.8 \{ filesrc location=test4.mp3 \} ! \{ queue ! mad !
audioconvert ! osssink \}
gst-launch-0.8 filesrc location=test4.mp3 ! id3tag ! mad ! audioconvert !
osssink