I watched in both & I have a 30" screen. Perhaps I need glasses.
You only have 2 java's listed in your preferences. I have 4 on mine. Java SE 6 64-bit, J2SE 5.0 64-bit, J2SE 5.0 32-bit, J2SE 1.4.2 32-bit.
So it appears Stief is right, Java 6 (1.6) is unavailable to non intel users. After some quick research
About Java for Mac OS X 10.5 Update 2 it appears Java 1.6 is only available for intel macs because it's designed in 64 bit.
Your mac is not an intel mac right? That's why you would not have 64 bit versions of java.