Wrong dependencies generation with M2Eclipse plugin?

[Francesco Furfari]

Hello,
I recently rebuilt my Eclipse environment for Felix.
I suspect that the Felix Main Project is not built correctly using 
eclipse:m2eclipse.
In fact, importing the generated project in Eclipse  the BundleActivator 
class is not resolved.
Adding a dependency with the "org.osgi.core" project fix the classpath 
problem in Eclipse.

However, I noticed that many times the org.osgi.core artifact is 
excluded from the dependencies inside the Main pom ,

     <exclusions>
       <exclusion>
         <groupId>${pom.groupId}</groupId>
         <artifactId>org.osgi.core</artifactId>
       </exclusion>
      ....

Any body could explain this to me ?
Do you think it could be the reason for the bad project generation?

thanks,
francesco