That's strange. It should be able to switch tracks pretty well on Sony Blu-ray. It even should pass-through DTS to your receiver.
If you send me a log as described here http://player.gtvbox.net/sendlog
I'll try to check what is happening.
I don't have a Sony Bluray yet, but as I remember it has different pass-throung settings for Dolby/DTS. Could it cause your issues?
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My devices: Logitech Revue, Sony NSZ-GT1 (rooted), Sony NSZ-GS7, Vizio Co-Star, Hisense Pulse (rooted), ASUS Qube and some others...