Resource copying from javadoc dir is incomplete

The plugin is ignoring my directory src/main/javadoc/resources

I want to put in background images for my stylesheet to use, and I want to overwite inherit.gif (to one with a transparent background, a Java problem since I started with Java back before 1.0, sigh). So I put a bg.gif and a new inherit.gif in src/main/javadoc/resources. It is not copied. I do have <docfilessubdirs> set to true.

I have attached a subset of my project that demonstrates the problem. Unzip and then run mvn javadoc:javadoc. If you look at target/site/apidocs/resources, the file contains only one file, while src/main/javadoc/resources contains three.