I made friends with the independent Nyunyu and they eventually asked me to colonize the planet in their system.
A few turns later they asked me to destroy the colony in their system that they thought of as a threat. I personally believe that they should never ask you to destroy your own colony unless you colonized it without their permission.


On a side note: For all the money and resources one puts into cultivating a friendly relationship with an independent planet the bonuses received from said planet should be a little greater. Not necessarily more money or research, but some positive diplomatic reactions from other races. Also players who destroy an independent system should perhaps receive a negative diplomatic reaction from some races.

I had a similar problem (funnily enough with the Nyunyu as well). They invited me to colonize a planet in their system, and then a couple of missions later we were allies. Then they suddenly broke off the alliance and I received a notification that I'd colonized a planet in their system against their will. My relationship with them plummeted to the second last red bar and their status was 'angry'.

I'm not sure if this is a problem unique to the Nyunyu, but clearly somewhere along the line they're forgetting that they gave permission to colonize their neighbouring planet.