Got tired of fighting against the brokenness of the old broken RedHat installation, replacing it with a daily build of Ubuntu Edgy Eft. This was actually a couple of weeks ago, but nevertheless. The installation was quite easy, fortunately I had 3 different installation medias, out of which one worked. One of them was a DVD, which would've worked, but after first boot from the DVD, my DVD-drive decided to be a CD-drive, and no longer agreed to read the DVD. The other CD had some kernel/userspace incompatibility problem, and would not boot. This is what you get, when taking daily builds.
To be exact, the RH installation is not gone, it still lives on a HDD that is not used for booting anymore. I used one of the storage drives to make the new installation, this gives me more time to find what's useful and what is not. It was only after the installation that I realised, the instability problems were actually not software errors, but rather exessive dust between heatsink and the fan. Well, the new ubuntu does many things that were b0rked in the RH. But it doesn't turn off the computer on shutdown, maybe I need to look into a BIOS upgrade.