FF3 on a DVD - Win XP&Vista situation with Extensions

Im using the FF 3.0 Portable on a DVD to be executed on XP and Vista by autorun to give a seamless execution and easy feel of use.

I already saw the recommendations on :

http://portableapps.com/support/firefox_portable#performance
http://portableapps.com/support/firefox_portable#cd

And almost everything works as expected

The problem.

On some machines, when FFportable begins the window of "New Extension Installed" appears on screen, because it detected installed extensions on the machine ( like the Windows .NET assistant, Flash, java, whatever )

Is there a way to avoid this? a save-mode option or something for it to ignore those extesions or ignore that installation?

The only solution I can see is to install all those major extensions on the machine I setup the FFPortable and only after that record it to a DVD, but even so, there is always the change for other extensions to pop up the "New Extension Installed".

Any tips?