I am thinking reserved word for cookie name

[root@orchid:Active] config  b version|grep -iA 1 version
BIG-IP Version 10.2.2 852.0
Hotfix HF1 Edition

[root@orchid:Active] config  b virtual bar list
virtual bar {
   snat automap
   pool foo
   destination 172.28.17.89:http
   ip protocol tcp
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@orchid:Active] config  b pool foo list
pool foo {
   members 10.10.70.110:http {}
}
[root@orchid:Active] config  b rule myrule list
rule myrule {
   when HTTP_RESPONSE {
        if {[HTTP::cookie exists "PD-H-SESSION-ID"]} {
                log local0. "I see PD-H-SESSION cookie"
                HTTP::cookie expires PD-H-SESSION-ID 30 relative
        }
}
}

[root@orchid:Active] config  curl -I http://10.10.70.110
HTTP/1.1 200 OK
Date: Mon, 14 Nov 2011 20:57:27 GMT
Server: Apache/2.0.59 (rPath)
Last-Modified: Sat, 11 Jun 2011 00:31:47 GMT
ETag: "667a-67-cfb682c0"
Accept-Ranges: bytes
Content-Length: 103
Vary: Accept-Encoding
Set-Cookie: PD-H-SESSION-ID=1234567890
Content-Type: text/html; charset=UTF-8

[root@orchid:Active] config  curl -I http://172.28.17.89
HTTP/1.1 200 OK
Date: Mon, 14 Nov 2011 20:57:34 GMT
Server: Apache/2.0.59 (rPath)
Last-Modified: Sat, 11 Jun 2011 00:31:47 GMT
ETag: "667a-67-cfb682c0"
Accept-Ranges: bytes
Content-Length: 103
Vary: Accept-Encoding
Set-Cookie: PD-H-SESSION-ID=1234567890;expires=Tue, 15-Nov-2011 05:57:41 GMT;
Content-Type: text/html; charset=UTF-8

[root@orchid:Active] config  cat /var/log/ltm
Nov 15 13:57:11 local/tmm info tmm[4878]: Rule myrule : I see PD-H-SESSION cookie