Problems with persistence and JSESSIONID?

I have seen situations where the server id numbers after the jsessionID change, which would create a different persistence record. To combat that, just strip out the jsessionID from the cookie:

 
 when HTTP_REQUEST { 
   if { ![HTTP::header exists "jsessionid"] } { 
     set jsess_uri [findstr [HTTP::uri] "jsessionid" 11 "!"] 
     if { $jsess_uri != "" } { 
       persist uie $jsess_uri 3600 
     } 
   } 
 } 
 when HTTP_RESPONSE {  
   if { [HTTP::header exists "jsessionid"] } {  
     set jsessID [findstr [HTTP::header "jsessionid"] "!" 1 "!"]  
     if { $jsessID != "" } {  
       persist add uie $jsessID 3600 
     }  
   }  
 } 
 

you might have to tweak this, I haven't tested jsession stuff in months and no longer have access to do so anyway. HTH