I'm a little concerned about something. After rooting my S7, every time I tried to move a file into /system/bin/ I would get a "Read-only file system" error. I rooted the device using the UniversalAndRoot app. After reading around, I decided to unroot it and uninstall the UniversalAndRoot app. Then I installed z4root and re-rooted the device using z4root. I am still getting the same "Read-only file system" error when I try to do anything that requires write permissions. As far as I can tell, the only place that I can write, even as root, is the sdcard. Has anyone else had this problem? If so, what was the solution?