Yesterday Asterisk-188.8.131.52 has been released, unfortunately latest irroot’s T.38 patch is still against 1.8.8. Since I’m going to upgrade my asterisk box I made a new patch out of his subversion branch and I ported it to 1.8.11. I still didn’t test it properly, but I will in the following days. Debian Squeeze packages of asterisk 1.8.11 with t38 gateway patches (plus some more features and fixes) will follow soon, expect them in the following days.
Here is the patch: http://files2.linuxsystems.it/asterisk-184.108.40.206-t38_gateway.patch
Please let me know if it does work for you.