Still working with a lot of Eclipse views, I got today a really strange behavior … The Window -> Show View menu creating my multi instance view with a null secondary id didn’t generate a call to the createPartControl method of my view !!!!!!
After several debug sessions I decided to clean my runtime workspace and the problem went ago. I guess this workspace was in a wrong state resulting of a lot of open and “dirty kill”.
Conclusion, just keep your runtime workspace clean when developing eclipse plug-ins.