Could not find method XXX, referenced from method

I have two android projects, ProjA requires ProjB (in Eclipse Properties > Java Build Path > Projects > Add > ProjB). Every thing compiles ok in Eclipse, but when I run ProjA I get an error:

Could not find method XXX, referenced from method YYY.

Where XXX - is the method from ProjB.

How can I fix the settings?

I have a similar problem when using external jar (in my case openCSV). The reason I had a problem was due to a change in ADT 17 (or above). What I needed to do to resolve the problem was

1. In Eclipse go to Properties -> Java build path -> Order and export.
2. Mark my jar.
3. Move jar to top of the list.

The solution was found in the following page which reference to a very good article.

還須要clean一下。