Hoverbod

I have just put my 2002 STI UK engine back together (someone previously took it apart) and there is a major fuel leak from the joints between the top of the injector and the fuel rail, on both rear cylinders.
I've had two ideas:
1: The seals have dried out
2: There is a fault with the fuel pressure regulator, not allowing fuel to return to the tank correctly.

Does anyone have any ideas, suggestions?

edit:
I should add, the manifold wasn't dismantled, so I don't think it was me putting it back together.
Jamie