Hello edtyre,
As I reported it in another post, I sometimes have the same problem, also solved by changing folder's name. In my case, import problem is due to sign ";" in folder's name (most of the time, import does work, even with sign ";" in folder's name, but sometimes - quite rarely -, sign ";" won't allow JRiver to import files located in the folder correctly.
Like you did, I managed to fix the problem by changing folder's name but, personally, I would prefer not to do that.
May I ask you what did you change in folder's name to fix the issue ? Is your problem due, like me, to sign ";" ?
Thanks.