I just bought a WU-1a Wi-Fi adapter for my D7100, and I have discovered that GPS data is not being recorded correctly on my downloaded photos. Regardless of whether they are new shots or ones I have downloaded manually from the camera, the Latitude data is recorded correctly but the Longitude is recorded as 0,0,0.0 so all my photos appear to have been taken somewhere in the middle of Algeria!
I'm using the latest IOS version (188.8.131.5201) of the WMU app, and the adapter has firmware 01.03. I've tried the app on both my current iPhone 5S and my old iPhone 4, with the same results on both.
Unfortunately I don't have access to another WU-1a or another compatible camera to be able to check whether the problem is with the device or the application, so I thought I'd ask here if anyone has experienced a similar problem.
I took my D7100, WU-1a, and iPhone back to my local camera store, and tried it with another WU-1a they had in stock. Same result. I'll try to find a friend who doesn't mind installing the WMU app on their Android phone so I can test that platform as well, but it appears that the iPhone app has a bug that's preventing the longitude data from being recorded.