I haven't quite figured out what the rules are for Elerium and Durantium.  Somtimes I can build ships that require them, sometimes I can't.

As far as I can tell, all that I should need to do is build a starbase near the respective resource, and in theory, all my starports should magically get access to it.

Does anyone know how these are actually supposed to work?

As an example, sometimes I go to my starport and in the quick build list is a ship that requires Elerium.  Sometimes I go back to the same star port, and I can't select that ship, but it's still in the build queue and will continue to build them even though I can't select them from the quick build list.

Likewise, if I go to th "manage" screen for the starport, sometimes I can select a ship that requires Elerium, and other times for the same star port it's grayed out without saying why.

As an aside, I also discovered quite by accident that building a "Constuct" [sic] spaceship and moving it to a starbase allows me to be build starbase modules.