Cannot partition Hard Drive in Mavericks Virtual Box

I am trying to re-size the HDD on my Mavericks virtual machine. I already used VBoxManage --resize on the host computer to re-size the .vdi. Now, when I go to partition the HDD to the larger size on the guest OS using Disk Utility, it doesn't give any errors but it won't partition the HDD. It acts as if it will make the partition and then it just goes back to the same size it already was. Any thoughts?