Troubleshooting, enabling new functionality in, or patching a ridiculously expensive piece of software managed by a ridiculously large team of technical people.

ETA: I understand that those one or two hours are potentially capable of making up the rest of my salary, at least from the perspective of someone who might want to pay me to perform such a duty, but I would also state that the lack of general feedback for the other 38 to 39 hours, and the requirement to show up to the office and generally pretend not to be blatantly non-busy, is akin to the problem humans have with large numbers: it's very difficult to feel like I've accomplished something for a few, tiny moments of work involving check boxes and following documentation, and it's highly irrational that I have to pretend I'm getting paid for 8 hours of hard work a day, when all they really want is 1 per week. That's in addition to the fact the dollar amounts involved invoke the large number problem itself...