Why do the high-mem webstarts not work?

Full question: 
I wanted to try the "High memory webstart". But non of the webstarts work - at first it seems like Java 6 is loading, but than I get an error massage saying "Could not create the Java Virtual Machine".

The high-mem webstarts only work on 64 bit machines with sufficient memory. The error you receive is because Java was unable to allocate the requested memory.

1) Either because you don't have that much memory.

2) 32-bit Java on Windows can only allocate up to 1.2gb reliably, it may work up to 2 or 3 gb on Linux/mac os 32 bit. On the latter two I'm uncertain of the exact limits.