The blueprint-maven-plugin (1.4.0) will currently silently pick one or another of two (or more) singleton annotated classes with the same name for the <bean> with an identical id=xyz to generate. This is VERY confusing...
This happened to us (in OpenDaylight) when we had a @Singleton class Something in package a; in one project, and another identically named singleton class in another package in another project which was a dependency of the first project (but both packages started with the same scanPath we use). But it probably even happens if you have two classes of the same name in different packages in the same project (not tested).
In an ideal world, such conflicts such lead to a build failure with a clear message.