Can't partition startup disk in Mavericks for Boot Camp
This indicates that the partition map on the drive is corrupt and needs to be repaired.


Backup all your data (possibly with a disk image of your startup disk partition) and boot into a separate disk (not Recovery HD).
Select your drive in Disk Utility, and choose the Partition tab.



Change Partition Layout to 1 Partition or 2 Partitions. This will erase the entire disk, replacing the corrupt partition map with a new one.
Click Apply.