Just to confirm what I see.... I have 2 VU+Duo's. At all times I can view the recordings from my Windows 7 computer which are on either Vu+Duo. When I have VIX Kernel 3.1.1 Build 24 installed, I can view recordings on the "remote" VU+Duo. When I upgrade one unit to Kernel 3.9.6 Build 89, I can still mount the share on the "remote" VU+Duo but when I attempt to browse the files it reports "no displayable files on this medium found". However, I can still view files in the reverse direction i.e. by looking from "non upgraded unit" I can see recordings on the "upgraded unit".
Thinking that the problem needed me to upgrade both units, I upgraded the 2nd unit, however the problem now occurs in both directions. As soon as I return both units to Kernel 3.1.1 Build 24, everything works again as expected.
From memory this started problem started about build 25 or soon after, and I've been too busy to look at if for a while.