Then it will be simple enough to check the rejected file for errors. You know as well as I do that your program takes a delay as a fail.
It's not "Delay" that makes this fail. It's outright failure to talk to the data folder. Windows reporting "sorry, not here". Even then I don't know if this is what's happening to you. I'm just guessing. If your theory's is correct, manually opening the data folder with explorer before you start Newsbin would be all you need to solve this problem.
To be clear, I don't really know what your problem is. Everybody else and his brother can change the data path and it sticks. So, the question is what are you doing differently? So, my comment about reverting the datapath, that's just a guess. You say your drives never spin down. If that's the case, my guess is wrong. Got nothing else to go on though so, it's on you to figure out why it's happening then tell me.
Until you characterize the problem and let me know when it tends to happen, there's nothing I can do. I'm left with one guy reporting that his data folder is moving with no kind of way to trouble-shoot it. All I'm getting from you is "it doesn't work" which is pretty useless for trouble-shooting.