Another thing you may want to investigate:
I am experiencing this issue for devices running Motoblur and updated to 2.3 (especially Droid2, DroidX and Atrix with Verizon).
The Camera parameters were fine, but in layout/capture.xml the background of the ViewfinderView is set to transparent:
Well, it looks that transparent for Motoblur on Android 2.3 is not that transparent...
from the ViewFinder solved my problem.