First, the problem of the missing prefix.
If you consume something in your layout file that comes from a third party, you may need to consume its prefix as well, something like "droidfu:" which occurs in several places in the XML construct below:
<com.github.droidfu.widgets.WebImageView android:id="@+id/webimage"
android:layout_width="75dip"
android:layout_height="75dip"
android:background="#CCC"
droidfu:autoLoad="true"
droidfu:imageUrl="http://www.android.com/images/opensourceprojec.gif"
droidfu:progressDrawable="..."
/>
This comes out of the JAR, but you'll also need to add the new "xmlns:droidfu"
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:droidfu="http://github.com/droidfu/schema"
...>
or you get the unbound prefix error. For me, this was a failure to copy and paste all of the supplied example from the third-party library's pages.