probleme in the session ID

the session ID doesn't apperied when i try to acced to .jar file

this the my logs

Fri Dec 12512:32:39 GMT 2014 alert local/tmm1tmm1[5083] Rule irl-pub_S1F2 : 

Access Allowed by public F5: normal request (Client IP: xxx.xxx.xxx.xxx) - HTTP Method: GET - HTTP HOST: xxx.1xx.1xx.xxx - HTTP URI: /Report.jar - HTTP Path: ReportViewer.jar - HTTP Query: - Client ID: xx.xxx.xxx.xxx: - Session table value:

correct logs for other link by the same irule but not for a jar file

Client ID: xxx.xxx.xxx.xxx:1FCF734F74BDCC11E3531DB181C52BBB - Session table value: CJX5cpRTUapNenCk+a9ibA==

this the bloc of my irule

if { $static::iRule_secWeb_verbosity == "3" } {
            set client_ip [IP::client_addr]
            set pretups_cookie [HTTP::cookie "JSESSIONID"]
            set client_id "${client_ip}:${pretups_cookie}"
            set lookupval [ table lookup -subtable "TABLE_AUTHENTICATED_HOSTS" $client_id ]
            set cook [HTTP::cookie "namecookie"]
            log local0.alert "User authentication success (Client IP: ${client_ip}) - Client ID: ${client_id} - Session table value: ${lookupval}"
        }

thanks in Advance