RTC 4.0 - AIX PPC 64 bit - problem with WebSphere generic JVM arguments

Websphere 7 fixpak 23 64 bit is up and running. I have configured everything the document calls for except on item.

In the Generic JVM argument under server1 it tells you to place the following variables,

-Xmx4g -Xms4g -Xmn512 -Xgcpolicy:gencon –Xnocompressedrefs

When I place these variables and try to restart server1 it crashes. The rest of the configuration that it calls out runs fine.

Any ideas why?  We have 8G of real memory.