Aside from problems with the TrackIR setup and the views setup, I'd like to add one thing: IMO, it's essential not to lose sight of your target, to "be in the cockpit" with your mind. When you fly, everything around you should disappear and you should feel like if you were in the cockpit. If you can think in this way, it should be natural to "turn your head" (i.e. select the right view) in the direction in which the target goes.
If you don't fly "in the cockpit", if you're not there, I think you'll always find difficult to keep track of your target: that's why I think Krusty's advice can't do any good (sorry, K, I don't want to criticize, just stating my opinion).
Of course, "being in the cockpit" is the first step: then you'll have to develop the right feel for the tridimensional space and the movement in that space, but that's something that comes almost always naturally (even though for someone is easier than for others).
Try changing the way your mind see the game, not the technical side of the matter (I never tried TrackIR, but it should come even more naturally to follow your enemy if you can "put yourself in the cockpit")