repeated problems with xar_session_info table

Hi,

I manage a site where I'm repeatedly getting the "Undefined index:  
xarSession_isNewSession" error.

I can fix it each time by emptying the sessions table.  But it has now 
recurred three times in a few weeks.  I've never seen it occur more than 
once during the lifetime of any other site.

Does anyone know what triggers this problem and why might it have 
occurred three times in just a few weeks? 

Xaraya 1.1.3
PHP 4.4.4
MySQL 4.1.22

Thanks,
Ryan


-- 
Ryan Walker
www.WebCommunicate.net:
Insights and resources for effective websites.