I got a possible solution for the ringtone bug:

Solution:
1a: For Control-Panel-ProfileX users : Uninstall ProfileX and reinstall it once again.
1b. Reset the ringtone and all other settings once again. (Also in (Profiles) for ProfileX users).
2. Turn off N900.
3. Remove Battery.
4. Press and hold power button for 30 secs.
5. Replace battery and turn on the N900.
6. Check it by calling to your phone. (at least 5-7 times.)

//This solved my ringtone (Nokia Tune) problem.


@CSSU-T Team:
Hildon desktop is continously crashing when using slide to unlock from power button. Though it stops after a couple of screen on-off(s). It looks like an app is repeatatively closing. Is it related to T8?

p.s. I also have qtlockscreen on.