I used to own an Aztek and 9 times out of 10 when it did that, the nozzle was not on tight enough. Take the little wrench for the head and turn it a bit more tight and try to spray, don't force it TOO hard as it might not want to come off, but enough to know it is tight. Hopefully that will fix you up.
My Aztek did ok for me but there came a point when I felt like it was too much maintenance and that one of the brushes you see talked about a lot on here would do me fine. If you ever come to that point, figure out which airbrush you want, talk about it and tell some of the high points to that brush and how you could use the Aztek for overall painting and the other brush for the detail etc...
If she pays attention to how much you like what you do and sees the results she'll be like my wife and buy that brush for ya as a present sometime. Feelings are spared and you still get the brush you want. But use the Aztek and see how it can do for ya. I know many people here who do awesome work with it. Also if something isn't working right with it there are a lot of current and former owners here to help ya figure it out.
Good luck!!