Do other ships now also show the same problems?
I want you to type in the following in the console:
import ShipIcons
print ShipIcons.shipIconNames.has_key("metropol")
print ShipIcons.shipIconNames.has_key("Metropol")# Notice the different capital M, you may leave out this comment btw, anything from the # onwards)
Now, if either returns 1, then make sure that's the name you have entered in the ship plugin.