there's no line about ttyS2 in the dmesg.
can you lit up the blue led with:
echo > /dev/ttyS2
Regardingn hciattach, what if you replace csr by bscp?
Finally, also try pskey :
pskey -d /dev/ttyS2 -s 115200
it may give you some more information about the firmware the device etc.
If all that fails, can you try the custom kernel as explained on externe.net/zaurus/kernel ?