Comment 8 for bug 968216


can also confirm this bug.
Concerns normal Ubuntu 12.04 Desktop installation, and Ubuntu Studio 12.04 installation as well.
Verification on total 3 (somewhat older...) systems shows:
System 1: AMD Athlon 3000+ / Asus A7V880 (VIA Chipset) / NVidia GeForce 7600 GT /2G RAM: Crash as described.
System 2: AMD Athlon 2600+ / Asrock K7S8X (SiS chipset) / NVidia GeForce 440MX /1.25G RAM: Crash as described.
System 3: Intel Celeron 2 GHz (P4 architecture) / Intel i945 graphics / 512MB RAM : Installation succeeded.

So, it looks like an indication that AMD processors are affected. I will do another test with a 4th system, Athlon XP 2800+ / Asus A7V600 / ATI Radeon 9600 / 2G RAM to examine influence of NVidia vs. Radeon graphics.

From some experience I have already seen happening with some other packages:
Maybe someone could check the options with which the involved "ubiquity" and "Python 2.7" packages have been built... possibly they may have erroneously been built with SSE2 support included, which older AMD Athlon processors don't offer.