For anyone who is bothered that they can't decide one or more pairing e.g. E/I, S/N, T/F, or J/P then there are a number of things you can do to try and clarify your basic personality type:-
1) Think back to when you were in late teens/ early twenties. You were probably more true to your innate personality type then. Over the years some people learn the strengths of the opposite type. Older people often come out fairly balanced across the 4 different pairings.
2) Do some more detailed questionaires on the subject. There are quite a lot out there.
3) Ask someone else who has some experience of these personality type questionnaires.
4) Look at some of the detailed profiles of the different personality types and see what fits you best. e.g.
http://www.personalitypage.com/portraits.html
5) A small number of people probably are fairly balanced over one or more of the 4 axes.