DHCP and PPPoE

Problem:    
    Cannot set mode to DHCP or PPPoE when HA is on.

http://docs- legacy.fortinet.com/fos50hlp/50/index.html#page/FortiOS%205.0%20Help/HA_FGCP.081.37.html

Note: this is allegedly supported in 5.2.1 or higher, but there are other
problems with this firmware that prevent me from confirming this.

 **Update:** With 5.2.2 I can at least set the option, I don't know if it
actually works yet.

 **Update 2:** I can do PPPoE with a HA cluster. Fail-over has not been tested
as of yet.