To me the goal should always be to provide a fix within 1 business day.

This will limit the amount of overhead a bug can produce in terms of administration and follow-up actions (communication, tracking status, checking if a reported bug is a known issue, …).

Of course, this only works if you haven’t already built a backlog of open bugs which you should address in the (near) future. If you have, it might be a good idea to introduce one or more bugfix iterations where you shift your focus from adding functionality to stabilizing your product and improving the things it already does.

I guess most clients prefer a stable product with some core functionality in which that product does a great job over a product that does everything but does a poor job or where every action has an unpredictable outcome.