Been running CM9 20100930 with Siyah 4.1.5 for the past 2 weeks and it IS stable, but somewhat lacks the smoothness of the stock kernel.
Steps:
1. Downloaded cm-9-20121028-NIGHTLY-galaxys2.zip (verified MD5 checksum 553ace910b40df9fa2471c15bcb401f7)
2. Reboot into Recovery and created backup.
3. Flashed cm-9-20121028-NIGHTLY-galaxys2.zip
4. wipe cache partition.
5. advanced > Wipe Dalvik Cache.
6. Reboot.
MD5, check!
Something new here?
Back to the blinky-ghost kernel