Disk Utility and Boot Camp

During the process of partitioning my hard drive for Boot Camp, I choose the required size of the partition and click 'Partition'. However, it does not complete this process, I get an error message saying:

"Verification failed. This disk could not be partitioned."

"Use Disk Utility to repair this disk."

I then insert the installation DVD and try to repair the disk using Disk Utility, but the button is grayed out (inactive), any ideas?

Cheers