The short answer to that is, "it depends on the bug".

Seriously though, some bugs are so easy to fix you're ashamed that they ever were filed in the tracker. Others can be so bad that you literally spends months trying to track them down... and you get nowhere. From my own experience with canned software like this, it's probably not even a code issue. I imagine that some module configuration is set incorrectly, and/or is conflicting with another, possibly unrelated module. Suffice to say, this kind of thing is pretty low on the scale. In other words, "It ain't rocket-science!"