Merge fails with Disk Director 12

Trying to merge two partitions on the same physical hard drive, and when I commit, it starts to proceed then errors out, saying to run chkdsk. I ran check disk, and there are no errors. I finally went to the Disk Management tool from Microsoft, and did what I needed to do.

Curious why the error message, and why they suggested run chkdsk each time, when no errors were reported on chkdsk.

I also notice that when I bring up DiskDirector 12, that the drive would be identified not only with the Volume Name, but also the associated drive letter. I do not see the drive letter, (C, D, E, etc), listed anymore. Is this intentional?

Thanks for any thoughts on this