Custom DLL in SharePoint Solution 2010

I reference a custom DLL to a SharePoint Event Receiver solution. But, the event is not triggered when adding a list item. In the log file, an error log can be found:

Could not load type 'SAFP.SharedMethods' from assembly 'SharedMethods, Version=1.0.0.0, Culture=neutral, PublicKeyToken=5e96847a5abc7fb4'

As I have deployed the DLL to GAC already and included the assembly in web.config SafeControl, I have no idea what am I missing.

After asking my friend "Google", it tells me that something should be done on package inside SharePoint Project.

1. Click Package and then click Advanced button

2. Add additonal assmeblies

 

Then I upgrade the solution and everything works fine.