I’ve searched through the forum but couldn’t find exactly the issue I had. I’m actually surprised nobody seems to have noticed (also google doesn´t show any clues).
I’ve installed oSUSE11 from the Live CD and pretty much everything went smoothly until reboot. Then after the splash screen, computer displayed a black screen. I tried not to panic but it stayed like that for half an hour. Reboot, grub login appeared this time but still black screen. Ctrl-Alt-F1 worked and Xorg log showed some messages of open acpi failed.
Before rebooting with acpi off (in part because I didn’t remember the command exactly), I tried though to launch SaX2 and , after guessing it had to be launched from root, got it working.
Reboot, and everything now worked fine.
So, now it’s ok but what about a completely novice user on that situation. I have a pretty much vanilla hardware, with a x700 mobility radeon. Two years ago oSUSE10 was the only distro to boot correctly with it, and now the only one not to. And the worst is it’s not a driver or acpi issue, as SaX2 just had it fine. Surprising, after all the blinking screens during install, so it really seems as a bug.