fmincon does terminate at some point unless it gets stuck inside an iteration. what i am saying is that there is some logical explanation for the long total calculation time. it could be that you: a) have alot of variables for which you want to optimize so the default number of iterations is very large, or b) the computation time for each iteration is very large (or even that it gets stuck) or both.
but you will have to tell us more (some code maybe) if you want help. one thing you could do yourself is to let matlab display the results of each iteration.... with 'tic' and 'toc' you can also let matlab display the computation time for parts of your code
