After an update from both my system update (although the update wasn't an "android" update) and eyefi app update it no longer displays my .nef files. I have the Asus Transformer 101 and have been using Eye-fi with it on 4.0.3 for a while. It wasn't until both these updates that the preview stopped working. Also, I did add some other raw apps to my android device in an effort to allow posting to Google+ (which didn't help). The programs are RawDroid and RawPal Gallery.
To be clear, both updates took place between the last time I used the app and the next time. So I can't rule one out from the other. Maybe someone else that has a stock Transformer tf101 could comment.
I will try removing the other two apps and see if that helps. If not I will uninstall eye-fi and reinstall it. Oh yeah, the other thing is that I changed the location of the file location (thanks for this by-the-way). That may be a reason why I couldn't see files added last weekend but doesn't explain why I can't see files added today.