Sandbox convertDateTime doesn't reload the timezone

[kindsol]

It is my understanding that the standard JSF tag <f:convertDateTime>  
only loads the timeZone attribute once per session.

In my application, I allow my users to change their default timezone,  
however, due the the behavior stated above, my users need to logout  
then back in to see the timezone change take place.

I read (somewhere) that by creating a custom converter tag the  
attributes can (will?) be reloaded every refresh.  Seeing that there  
is a custom <s:convertDateTime> tag in the sandbox, I got that  
running -- but I am seeing the same behavior.

Any ideas on how to force the timezone Attribute to be re-read on a  
page refresh?

-Sol