Did you ever find a solution to this?
Just wanted to chime in and say that still is not resolved. Brand new Yuma 2 (Win7) with ArcPad 10.2 R2 (Build 50) can only take pictures from inside ArcPad at 640x480. Camera works fine up to the advertised 5MP outside of ArcPad though. I opened a case, and Esri support was able to repeat the behavior. It has as since been attached to this bug (NIM089150) and closed out. I'm seeing that this bug is now 2.5 years old with a severity of High. Crossing my fingers, but won't hold my breath.