Core-dumping show stoppers are usually easy to locate with the
debugger and some decent
detective work. After all, you have an event that provides a
built in break point for your
debugging.
Memory leaks are
just evil to find and fix in most cases. You start with little to no clue about where the problem is. You have to step through much of the code to even start to have a hope of finding the problem.
This sort of shite is one of the reasons I use C++. It isn't perfect, and you still use pointers enough to get into trouble, but it reduces their use to the point where you spend a lot less time groveling around for that leaking memory. Got bless destructors!