As it is hard to accept that Mac come across with serious issue, but occasionally this might happen and keys out of order Mac Lion is such an issue. This means that there is severe file system corruption in Mac which must be repaired. Sometimes out of order keys will result more problems when trying to copying items, finding files or removing files. In Mac entries are often in sorted form in the directory and Keys generally referred to directory entries. And there is particular named entry for each file, folder. As keys out of order mac lion exhibits serious file system damaged that's why it can be rarely repaired through disk utility. So in that difficult scenario reinstalling the OS X is the mere option. But make sure you have kept the backup otherwise there might be more troublesome would appear in the form of data loss. After resolving keys out of order mac lion if you encounter any sort of data loss then you can consider Mac Data Recovery for total recovery. It is the remarkable tool that ensures restoring of lost data from damaged, formatted hard drive in effective manner. So hope through implementing above mentioned measures you would resolve keys out of order mac lion problem.