FirefoxPortable 3.6 - Disable the "window add-ons"

Hi everybody,
I made a web site which runs on a USB Key on FirefoxPortable 3.6.The application works well even if everything is burned on CD. I nevertheless face the problem that on launching FirefoxPortable.exe the "window add-ons" opens up automatically notifying the installation of the extentions.
Having said that, here is the question: Is it possible to disable the automatic startup of window add-ons(may be by working on the config file)?

Thanks for your help.