Ubuntu for SPARC: Linux freezes (ALOT!)

Hi, I am wanting to get some input on an issue that I have encountered with Ubuntu 7.10 Gutsy. When installing Linux & booting Linux it freezes almost all the time, I don't know if it is the shell or whatever, but after SILO, it goes wild of freezes, then rebooting all the time. (The display changes to black and fonts are different) However, I don't have this problem in Solaris 10, and Solaris 10 is stable as a rock. Any help would be greatly appreciated.

My machine: Sun Blade 100, 1 GB RAM, 15GB HDD.