Ghost 15 - cannot create recovey point

Norton Ghost 15. I have 2 separate HDDs on the same machine, C & D. I can create a recovery point and incremental back up drive C - no problem. But when I try to create a recovery point on Drive D it stops. It will count down from maybe 30 minutes down to 18 minutes, then start counting back up again. I've tried this 3 times and once let it count back up to 2 hrs. Oddly, it always stops at 56,392,232 KB. Drive D is 107 GB and target drive has 1.2TB free space. I've tried chkdsk /r on Drive D as well as the back up drive. No errors. I can select files and back up, but not image the whole drive. Suggestions? How do I troubleshoot this?

 

Thanks!