List of some other Mac Disk errors

1. Invalid volume free block count

The volume free block count is a type of cache of the real information stored in the volume bitmap, and the count being off does not mean your volume is damaged in any way. An incorrect volume block count message (block count changed from X to Y) is an example of this type of message.

"Volume header needs minor repair"
"can't locate IOPlatformMonitor"

2. Incorrect block count for file

In the case of this message, you can erase the file and restore from the most recent backup if needed.
Resolution. Each of the messages above is benign, and indicates no damage to the file system. You may safely ignore them.

Additional Information
With a journaled volume you do not need to start up into single user mode. When a volume is made available to the file system, the journal is replayed and the file system brought up to a consistent state. If you do run fsck, it is best if you use -n and -f flags so that it will not actually modify the volume. Options explanation from fsck man page (short for manual page)

3. Incorrect number of thread records

It means that your disk's file system is corrupt - that some of the internal bookkeeping is inconsistent. Disk Utility can only fix some of these types of problems. When you encounter something (like this) that Disk Utility cannot fix, you need to use any third party tool.

4. Invalid header node

The "invalid header node" refers to corruption in the hard drive's directory, which is preventing the computer from booting from it. 
Stellar Volume Repair has the ability to resolve all these problems.