Zaq,
Can you get a file for what you are seeing because it might be minor country specific. Just ran a quick test with Sweden (Russian sponsored) v Britain and was able to place the fleets in a sea area adjacent to any port in Sweden (except for the ice zone).
Richard
It depends what you mean with minor country specific, i think the problem is not limited to Sweden as ive seen it before in 1.0 just never reflected about the rules/implementation aspects of this before the question of placement was raised, probably because no direction has been available on what rules to use until you made it clear that 4.6.3.5 from EiA apply.
I will try asap to figure out if it also applies to other minors but it might take some time to actually get control of another minor with fleet, i will also test if it applies to major powers wich is easy by just starting a new game with any major power with fleet factors available. I can provide you with a save of the game used in my example with Turkey controlling Sweden as a result of a russian DOW.
I never said it was a problem to place the fleet according to the in the manual printed 5.2 which sometimes can conflict with your 4.6.3.5 but the real problem is that it seems impossible to actually fill the fleet with any factors if it is in a sea area which makes the placement while possible and valid quite pointless.
Edit:
It seems like initial placement in the setup phase is not affected by this problem it seems to work as intended.
Edit2:
As England i got control of Portugal as a supporting major power when Portugal was DOW'ed by Spain. Portugal works consistant with Sweden from the previous example. and are affected by the same problems.