Yes, I added the registry key, and it worked to both a Windows share and an SMB (Data Domain target) share. (I was getting failures before on both.) One thing of note: Not sure why it is taking so long to run ...it took 50 minutes to do a simple file backup (first seed) of about 40 MB for both targets. Client, server and targets are all on the same subnet, 1GB lines, not heavy amount of traffic. . A incremental takes about 2-3 minutes for the same job, so a bit concerned how long a full backup will take. I will test that and update.
What is the registry key doing exactly?