[Epic 4G Q&A, Help & Troubleshooting] duce102:
The change log is linked in the OP of the CM9 thread.... try looking there before posting threads like this.....

http://epiccm.blogspot.com/p/cm9-status.html

Edit: just in case you don't know how to click a link here's the change log......

Changelog

CM9 alpha4 Sunday, February 19th, 2012

Fixed the much hated Ringing of Death bug. This was the short chirp before the ringtone, or constant ringtone that would play during or after an incoming call.

Fixed ICS multitouch protocol in qt602240 driver. This should make it possible to play certain multitouch games like Dead Space™. It also fixes the touchscreen driver with CWM 5.8+ (not released by koush yet).

LED notifications have been changed to enable significant power savings. LED notification has been changed to blink every 15 seconds, roughly matching the delay in Samsung's EL30. This alone eliminates ~71% wakelocks, while previously the CPU was unable to sleep at all while the notification LED is blinking.

LED notifications may be turned off entirely for additional power savings. Settings > Display > Pulse notification light. This allows you to continue to hear the notification chime and vibration without the added battery drain of LED blinking.

Adjusted heap settings to match crespo. This is very similar to a popular tweak in the forums. It prevents some Out of Memory crashes (i.e. NPR News). You can use these three lines in /system/build.prop to benefit from this tweak prior to alpha4.

dalvik.vm.heapstartsize=5m

dalvik.vm.heapgrowthlimit=48m

dalvik.vm.heapsize=128m

Dialer will no longer lockup in rare occasions.

Numeric battery % indicator now works!

CM9 alpha3 Monday, February 13th, 2012

Battery Related

Fix automatic brightness setting. In alpha2 you could save power by turning off automatic brightness and manually reducing brightness. This is fixed by updating the array values for brightness levels to match CM7 and stock. This reduces wasted power and hot screens reported by some users.

Capacitive buttons backlights (Menu, Home, Back, Search) now mimic TW behavior by turning off the backlight after a 6 second timeout. This both saves battery and improves the user experience in darkness.

Fix the power profile. Previously battery usage blame percentages were less accurate.

LED charging indicator no longer turns off after you dismiss a notification.

Switched to crespo kernel audio driver. The kernel audio driver (wm8994) now matches the userspace driver (libaudio) we added in alpha2. Should hopefully resolve speakerphone mic issues.

Voicemail default number is set to your phone number and not *86 by default on new installs.

MMS now shows profile faces.

Fix roaming bug. Prior to alpha 3 opening Mobile Networks settings unintentionally disabled roaming. Folks upgrading from alpha2 should open System settings and ensure Auto: Domestic Roaming is selected to enable roaming support.

Added roaming options. Alpha3 includes domestic, international, both, and no roaming options as found in gingerbread TW ROMs.

Fixed the annoying "Data usage warning" that was previously impossible to dismiss from the notification window.

Removed Chinese and Japanese IME. Install the better IME's from Android Market if you need Asian language input.

CM9 alpha2 Tuesday, February 7th, 2012

With alpha-2 and all future versions of CM9, you will no longer need to update gapps after every upgrade. It is highly recommended that you upgrade to the new gapps-ics-20120201. This new gapps-ics has the face unlock split into a separate .zip because it is rather large and not very useful with our low resolution front camera.

4G WiMax curtain toggle. If it doesn't appear automatically, you may need to manually configure it in Settings > System > Notification drawer > Widget buttons > Toggle WiMAX.

Video recording longer than 1:45min retains A/V sync.

"Call has been lost." popup no longer occurs on a far-end call hangup.

libaudio ported from crespo (Nexus S), resolves audio distortion during phone calls and improves Bluetooth audio quality.

Re-enable SEC_ADJUST_LMK in kernel to fix the low memory killer. There was a problem where kswapd0 went crazy needlessly consuming cpu, killing performance and wasting battery.

Manual brightness setting slider now works.

Changing camera resolution no longer crashes the camera app.

CM9 alpha1 Tuesday, January 31st, 2012

Location services - it was causing the CPU to spin for a long time wasting power.

Soft Keyboard dismiss when slider is open.

CWM scrolling

CM9 alpha0 Monday, January 30th, 2012

Initial release