[Pan-users] Proper behavior of "backup" servers?

[walt]

While testing pan's new ssl function I discovered that setting gmane.org 
to "backup server" prevents pan from ever asking gmane for articles that 
I click on in the header pane.

Using a packet sniffer I can see pan requesting the articles from my 
primary server, which then takes about twenty seconds to return "article 
not found".

At that point shouldn't pan then request the article from gmane as a 
backup server?  Do I misunderstand pan's definition of "backup"?