Why Planet refuses to build?

[DavidG]

Does anyone know the reasons a planet will not build. I'm playing with a guy who swears the game is 'screwing him'. The reasons I know are lack of resources, lack of population, planet riots, lack of cargo space. Are there any others? The planet in question is his home planet that was bombed and had all mineral facilities destroyed and he is trying to build a weapons platform. But he has resources from other planets. Apparently the item gets added to the build queue but next turn it is not there.