Hi all.Today I tested again the live cd, but now without starting Orca in the bootscreen. Ubuntu does the same (starts, plays log in sound, starts again and so) even without starting Orca. So, the problem isn't in orca, the problem is in the Ubuntu hardware compatibility. I post more details when I know more.
Verified. I booted my laptop with Ubuntu guzy live-cd and all is working smoothly. BTW, Orca has a lot been improved from Feisty. That's great! All is working better than ever. I hope that I can solve the compatibility problems with my desktop pc very soon.
Tuukka