Are you sure it's the 64 version ? There're 2 versions, one 32 bits and the other 64 bits, called UltraLinux... I think you should be able to run the 32bits with no problems too, but I'm not sure... give it a try !

With that OB version, you should have the command "limit-ecache-size", to limit the cache size to 4MB, but I guess the sunblade 100 has less than 4MB... try it anyway... at the ok prompt...