Note: Mospheiran = planet-born human
The cultural differences, the biological differences that had led atevi to attack the early settlers were continually with them...now known and laughed at, on both sides, but those differences still tweaked live nerves in moments of frustration.
A worker, human or atevi, who couldn't overcome his own biologically-generated anger and laugh at a situation, had to ship out--he got a quit-bonus for his honesty, but all the same, he had to ship out.
And thus far, years into the project, they'd only had to ship out--what, fourteen, fifteen, out of hundreds? Not too bad a record...thus far. The two species had changed their cultures to fit--somewhat.
They'd developed a stationside culture of interspecies jokes, that was one thing--some bawdy and some stupid. Mospheiran experts had wanted to silence them, but atevi had let them run, and the ship humans had contributed the framework and Mospheirans took to it. A human team and an atevi team had a contest, one such joke began...
There was a whole series of those, that usefully illustrated species differences, cultural differences, and made two species laugh. That was the good news. No one had gotten mad. That was the other good news.
We have to get along had become the common sentiment between humans and atevi aloft, at least.
Edited to add: Knew if I dug deep enough in the Interwebz I'd unearth this. An ancient archived thread from back when the above was first published (2001) where fans were trying to come up with atevi/human light bulb jokes: http://shejidanacherryhpit.yuku.com/topic/495#.UzTA3rlOUfI