In my program, only one LED of the whole cube lights, the only problem is that some are only supplied with 0.2V, unlike others, which are supplied with the regular 2V. I noticed that when one LED in a column is supplied with 2V, all others in the column are also supplied with this voltage. This means that either the LEDs of a column get 0.2V or 2V.
I do not think the problem is in my software which I would likely to be develop as an iphone app, but rather the circuit.
Can it be that the transistors may not properly steer?