After KDE SC 4.4.4 upgrade, plasma-desktop and other apps constantly crashes.

[CyberAngel]

System info: Kubuntu 64bit with KDE SC 4.4.4 installed from kubuntu ppa.
CPU: AMD 64 3500+ socket 939
RAM: 3GB (2x1024MB + 2x512MB)
GPU: Nvidia 6600GT using the open source nouveau driver.

Upgraded to KDE SC 4.4.4 using kubuntu ppa repository.
Since then, plasma-desktop, dolphin, ktorrent, konqueror even drkonqi crashes
when opening them!
The behavior is the following:
- plasma-desktop instantly crashes. Trying once to restart but crashes again
and then I have a black screen.
- dolphin, ktorrent and konqueror instantly crashes.
- drkonqi comes up with three stars of usefulness to file a bug report when
these apps crash, but when I reach the login page and press the login button,
even drkonqi crashes without any other instance of drkonqi to appear!!

all of the crashes looks similar having 34-38 lines of dump.

Luckily krunner still works and I can launch some applications from it.

The same upgrade didn`t have any similar bad side effects on my laptop that it
is an AMD Turion MT37 with 1GB RAM and ATI mobility radeon X700.

Anyone else encountering this issue?

Is there any way to revert back to the working packages using apt-get or aptitude?

Thanks,
Vangelis