master page does not change due to preinit event not firing

i am making an asp.net 2.0 ajax enabled web site that uses 2 master pages, one for administrative users and another for end users. the problem is that after signing out and signing in as a different user (from admin to end user, or vice versa), there are certain cases that the master does not change.

tracing the code during loading, i've found out that the preinit event no longer fires sometime (as this is the event where i dynamically change my master pages for content page).

is there any way to forcefully fire the preinit event each time the application redirects to any page so that it would load the correct master page.

any help is greatly appreciated.

thanks!

fchise

franchise63