According to DS9 (which I'm watching at the moment) there should be a Cardassian border) to the Klingon Empire. Let's blame it on the third dimension...
well maybe something happens in Voyager or after stuff that happens in original timeline in new Star Trek the Movie?
I think the problem is that they drew this map after the shows were done, Tolkien was smart enough to do it the other way around ;-). I wonder how the map is in the MMO.
On a side note, after nearly finishing DS9 (only last episode to go). I must say it is my favourite Star Trek show so far. While the series at a whole had some not so good episodes, the overall quality was very good. Especially the last arc is, so far, brilliant.