Android ImageView size not scaling with source image
What about changing your ImageViews to use android:layout_height="fill_parent"?
Edit - took me a while to find, but looking at the source helped me pinpoint adjustViewBounds. You might want to try adding android:adjustViewBounds="true" to your ImageViews. Surprisingly, this defaults to false.
Strangely android:layout_height="fill_parent" and android:adjustViewBounds="true" didn't help. The problem I had is image was getting displayed, but with block row on top and black row on bottom of image. Setting scale type to "centerCrop" helped me. I guess, the reason being my image size was small.
I had similar problem and my solution was to set android:scaleType="fitEnd" attribute of ImageView in XML layout file.