I am not sure what you are trying to do, so I don't know what advice to give. Why can't you call the initialization routine from whatever code you are writing?

The Initialize() function only has to happen once per application, but in order to be reliable I had to put in every place that might trigger an application start. The vast majority of times the handler is invoked the app will already be initialized and it won't need to run.

It is also possible to place the initialization in the Application_Start event in global.asax. I didn't put it there because I wanted to make it easy for developers to add the gallery to an existing app and I wanted the initialization to be self contained. Depending on your situation, you might find it easier to put it there.