Bug? Compile To Library

I suspect something is going wrong with the Compile To Library function.

These are the steps I follow:
- Clear project
- Compile To Library
The resulting JAR consists of a simple directory called "module"; which is correct

- Immediately Compile & Run the project and stop
- Without clearing the project, Compile To Library again
The resulting JAR now consists of TWO directories called "module" and "android"

Why the difference?

Where does these folders come from? Can you upload the jar?