I am fairly new with using android phones, and I am encountering that error when I am attempting to update Superuser. I'm using a Samsung Admire SCH-R720 Android 2.3.4 and I rooted it with the One Click root. I've downloaded titanium backup, Root Checker, and terminal emulator to make sure I am really rooted. I've tried uninstall/reinstalling superuser, installing the superuser update fixer(which said signatures matched), and clicking on automatic update. Current version of SU Binary is 2.3.1-ef and everything in the update is fine until it gets to "Copying su to /system... fail!". Superuser does request for rights when it asks to gain root access which I click on Allow. I am also not sure if busybox installed correctly or not, but the Root Checker program I installed said busybox was installed.