>My experience is similar, I taught 2 years of undergraduate lower-level math for mostly humanities-type majors that did not care for math much at all. And the realization that if I stayed in teaching, I was going to get a lot more of this, before I had enough seniority to get *real* math students who cared about the subject. So the satisfaction level was quite low, as compared to the nice quick results you get with a cool app working, as you describe (aside from the bug reports and enhancement requests, anyway :)
I remember I used to spend a couple of hours proving some theorem in geometry (I remember it was some Simpson, though I forgot what was it about), and the pleasure I had when I finally did it. Exterminating a nasty bug never lasts that long, but the pleasure is the same :).