Huanyang VFD won't save programmed values

Hi Commrades,
My CNC, 'RoboFang' is coming along nicely [ame="http://www.youtube.com/watch?v=NKcOlxT_4BQ"]RoboFang[/ame].. Amazing how time flies! I though't I'd be all done in a few weeks. Almost 9 months later I'm still going!!

Anyway now I am working on using the Huanyang VFD plugin to control my spindle over RS-485.

I entered the values into the VFD and then fired up mach3 to test.. the values didn't appear in the config box as described in the plugin instructions, so I spent about 2 hours trying to test and fiddle with the serial port.
No issues there..
Wiring. Check.

I rechecked the VFD and found;
PD163 : 000
PD164 : 1
PD165 : 0

Which is wrong. They should all be set to "1", "1" and "3"

I hope I am doing something screamingly obviously wrong.. I do the following;
press "PGRM"
Then select PD163
press "set"
press "^" [display reads 001]
press "set"
press "PGRM"

Then I go back into PD163 and it's still set to "000"
urrrgggghhh!!!!!!

Same goes for PD165

Has anyone else had this issue? Bouncing the power to the vfd on and off doesn't help.

PD001 and PD002 are set to 2 ok, but I do recall that took some fiddling too. Can't remember what I did, but I do recall it said "end" after I press set rather than incrementing to the next register ie.. PD1003

I have not tested the VFD readback, but I have solved the VFD not saving values issue.
PD001 (paramater lock) was set to 1 = lock
I changed it to "0" = unlock - and now parameters are saving!

Knew it would be something simple!