Debug mode heap diagnostics improved. Write before/past block checks are now more accurate.
Memory leaks now list a "memory breakpoint" value. Add this value to commandline (e.g. "--memory-breakpoint__ 107749") and the U++ will stop at corresponding "new" statement with segmentation fault (something you can catch with debugger and see the call stack). (Of course, if you are about to detect the real culprit, the code must do exactly the same thing..)