If you wanted to boot from a GPT SSD disk, you must boot from the openSUSE 12.3 DVD in EFI mode and at least for me, RC1 did not work in EFI mode, the display was unreadable. Further, for a small SSD of 128 GB or less, why even bother with a GPT disk? Sounds like you are going down a road that is not going to work, because openSUSE 12.3 RC1 has GPT problems and because it does not sound like you booted openSUSE 12.3 into EFI mode. I suggest for a SSD I wanted to boot from, to stick with an MBR disk. Have a look at the difference here (at the end is a how to link to convert a GPT disk back to MBR):