There is a bug in the Sun Crypto Accelerator 6000 firmware. Using the following versions (from 1.1 Update 2 for Linux (RHEL 5)):
Hardware : 1.4.50
Bootrom : 1.0.10
Firmware : 1.1.2
When you set the card to FIPS mode, you must use an UWK (USB wrapping key) in order to export the master key to an USB stick. You must then configure the UWK by entering 2 - 10 components. You tell the card how many components you want to use, but it will only ask for 1 component. The export will thus fail. I am using the serial interface, so it does not depend on the software in the OS.
The only way to export the master key is not to use the FIPS mode.