Chris,
Some questions:
When you are trying to switch to photo, are you selecting the camera icon at the middle right side of the ST16 display?
Is it the above action that is not working for you?
Also, when in video mode, it seems you are saying the photo button works to take a photo. Is this correct?
Last question: when you ARE able to get a photo taken, what are the file sizes you are seeing?
Reason I ask is, at least with my aircraft: when in photo mode, via the aforementioned camera icon selection, the file sizes are around 12mb, if memory serves correctly. When in video mode and pressing the photo button, the images are lucky to reach 1mb.
Important if one needs the resolution!
Jeff