I am having the same issue with my LG Spectrum 2. The photos I took were saving properly only a fraction of the time. When I brought it back to Verizon, they said it was a hardware issue and replaced my phone--but not the SD card. The first few photos I took on the new phone saved properly, but then they stopped saving properly. So, I went back to Verizon and they told me this was an LG issue, so I contacted LG. LG said that they weren't responsible for the problem because they're only responsible for the phone itself and if I'd gotten a new phone and still had the problem then it wasn't the phone, it was the Android software and/or the SD card, which they said they weren't responsible for, that it was Verizon's issue.
Just a few days ago, the phone said the SD card had unexpectedly unmounted and all the photos disappeared. So, I thought maybe the SD card is the problem. So, I took it back to Verizon and they said to contact LG because they're not responsible for the SD cards--ugh! Now, seeing your post, I'm concerned that even if I go to the expense of replacing the SD card, it still won't work. So frustrating! Did you end up finding a fix? Should I try a new SD card and hope for the best or is the LG Spectrum 2 just not the way to go? I've not really had any other issues with this phone, so I'm reluctant to replace it and would just love it if I could take pictures that were saved! Thanks for your feedback.