Sharepoint Timer Job succeeded but didn't execute the code

Question

I have a custom Timer Job created in Sharepoint 2010. After it runs, the Status shows "succeeded", but it actually doesn't execute the code.

I have managed to debug it, and I saw that it enters in the "empty" constructor several times:

public MyTimerJob() : base(){}

and then it stops, without entering in the constructor with the parameters:

 public MyTimerJob(string name, SPWebApplication webApp,SPServer server, SPJobLockType lockType)
          : base(name, webApp, server, lockType) { }

and avoiding the Exectute method:

public override void Execute(Guid targetInstanceId)
{
  mycode();
}

Any suggestions?

I have already

• restarted the SharePoint Timer Service from the Service Tool
• restarted SPTimerV4 from the console
• checked the Application Pool
• killed the OWSTIMER.EXE
• checked the rights of the user which is running the Timer Job
• tried to deactivate/activate the feature