I got hold of most other distros available. Fedora, Knoppix and *buntu won't work, but:
Opensuse, DSL and Puppy (all latest stable releases) work just fine.
So my conclusion is that if there is a problem, then I guess it's not on my side
I like using *buntu for the ease of use and great software and documentation support, but it seems that on this particular machine I have to use Opensuse.
Anyway, I'm going still to try some more live distros and post here news as I have them.
BTW, Debian ETCH v 4.01 also works, but when I upgrade to lenny or sid, it freezes during bootup.
There's something strange either with my MB, or with this new Debian-Based distros, and I can't figure it out.