@HerrNiemand:
I think I know what you mean. From "Weird Island" you go Eastsoutheast to a much larger island, then Southeast to a weird shape (it's a set of locks, but that's difficult to recognize if you don't know it), right before the first red bonus. Now, straight down is your "4", right?
In fact, that's just an island which (presumably) is also not a part of any municipality. Hence the black outline; in the original .svg all outlines are black (well, I don't know for sure, I guess they are), but territories have their colour overridden by WL based on which bonus they belong to. So when you have a shape that's not part of any territory, it will keep it's original black colour.
Of course you don't have to take my word for it, but would you trust [Google Maps](
http://maps.google.com/maps?ll=51.69448,4.377022&spn=0.139816,0.445976&sll=46.051426,14.505965&sspn=0.313086,0.891953&t=m&z=12)? :p