What is the best way to debug A/V out of sync?

[marcin at saepia.net]

Hi,

I have pipeline that looks like this:
http://img853.imageshack.us/img853/4374/videoeos.png
I don't know there's no sync=true marked on sinks, but sync is enabled.

It shows state right after item0_video_parser got EOS (I catch it via
pad probe) and before blocking it's src pad. After it blocks I
dynamically remove item0_BIN and replace it with similar bin, preroll
and link again to the rest of the pipeline.

The problem is that second, third and all of the next videos run out
of A/V sync. What is the best way to debug such case? About what I
should be especially cautious in the logs?

Thank you,

m.