T5: onActivate error handling?

[D&J Gredler]

Hi,

I'm using the activate / passivate infrastructure in T5, and have a question
about it. I have the following methods on a search page:

   public String onPassivate() {
       return this.jurisdiction;
   }

   public void onActivate(String jurisdiction) {
       this.jurisdiction = jurisdiction;
   }

This works for URLs of the form "http://www.host.com/search/atlanta";.
However, if a user ever goes to "http://www.host.com/search";, he will get an
ugly error page for an IllegalArgumentException, with a message like "Method
com.of.pages.AbstractJurisdictionPage.onActivate(java.lang.String) has more
parameters than there are context values for this component event."

I'd like to be able to handle this condition myself, and thought I might be
able to do so if I added a parameter-less onActivate( ) method, but no
cigar:

   public void onActivate() {
       // redirect to home page, or use a default jurisdiction
   }

What are my options here?

Daniel