Hi hawhill,
Yes, you're exactly correct. I just came back to update everyone in case someone else stumbles across this thread.
The actual problem was to do with the fact that the app was unnecessarily
requiring a camera feature (potentially auto-focus but that didn't entirely make sense as it appears that the Arc 7 has one).
Changing the camera to
Code:
<uses-feature android:name="android.hardware.camera" android:required="false" />
in the manifest did the trick.
Thanks everyone for your help.