I have downloaded both the 32 and 64 bit versions of 12.1. I’m having the same issue with both. I have used the DVDs on an older Compaq Presario, AMD Athlon 64 3200+ with 2Gb memory, 150Gb IDE HDD with no problems. The PC I really want to use is the issue. It is an HP Pavilion Elite, AMD Phenom II X4 with 8Gb of memory, 2 1Tb SATA HDDs not set up as Raid. When I boot up to the installation menu and select Installation, the Kernel starts loading and at the end of the Kernel load the PC reboots and starts the process all over again. Currently have MS Windows 7 Ultimate running and wish to dual boot. Have been running dual boot with Linux Mint, but, want to switch back to openSuse, have been using it for years, and want to go back.
What I would try, I’d choose a different Video Mode with F3 key when the “openSUSE installer” menu comes up: first try some other resolution, then try VESA, then try text mode. Try different modes. For example, I had to install with Text Mode and put up the graphical interface later on. If you have time, and if you have the opportunity, try version 11.4. I like 11.4, and it seems to be more stable.
Also, maybe you have to blacklist some video driver, try searching the internet for information on your video card in connection with Linux.
Have you run md5sum <name of .ISO> after downloading ISO file? Also, run the media check to see if the problem is with the DVD.