You don't see game development positions on general programming job sites because good candidates don't come from there. With few exceptions (web/database guys, for one), game programming is such a different beast than the majority of programming jobs out there. And "game programmer" is one of those "sexy" titles that has a lot of casual people throwing their hat into the ring and not being good fits for it. Your signal/noise ratio from the responses would be crap. Not to mention, most [experienced] game programmers aren't looking at sites like that because they're not the kinds of jobs they're trained for or want to do.
Even if a person you find on a general programming site is a smart guy and can pick up on the topics, their salary expectations are probably not in the ballpark of what most game programmers make. Most people who have a cushy 100k/year programming job aren't going to take one with most likely longer hours and a steep pay cut.
So most game companies put their high profile positions on their own site and on game specific job boards like gamasutra. From the applicant's perspective, there usually aren't that many game companies in any given city (with a few notable exceptions like L.A.), so for looking for a job if you're not in a position to move you can usually get the short list and apply directly.
There are a few other places to get good people. Job fairs at game educational places is one. Booths at industry events (i.e. GDC) is another. If you manage to go to GDC, it's amusing to see the huge line for "students" vs "professionals" for the larger, well known companies out there.