[ubuntu] Disk Utility/Boot Camp not working when partitioning

Hi all.

I'm trying to do a dual boot of Ubuntu 12.10 and Mountain Lion. I see that all installation methods involve going into Boot Camp or Disk Utility to partition, but both are not working because of some "verification failure", yet I've checked for the hard drive to have no issues.

Is there a way to fix this, or at least bypass it and install Ubuntu with no hitches?