Not sure if you have solved this problem already, but just to add a little more information to this, we were seeing the same problem not only on gingerbread devices, but also on ice cream sandwich(4.0.3 and 4.0.4) devices.
Followed your advice, added android.aaptOptions.useAaptPngCruncher = true and that fixed our build for now.
We noticed that this caused an error with a bunch of png files pulled into our apk from Appcompat (rev 19.0.1). Today, we rebuilt code that was working with gingerbread and ICS devices on Tuesday (noticed a dramatically increased apk size ~30% larger today), diffed the apk contents, saw that the png files from AppCompat were the only files that were different between the good and the bad apks. Then I ended up finding this post and your fix.
Hope that helps.
Thanks for the fix!