Hiya all tried to answer back to my last post but it kept timing out maybe it was too long - anyways I just wondered if there was anything else i can try :(
If port 8180 keeps the sessions but port 80 keeps recycling sessions surely it must be an issue with mod_jk I have also tried mod_jk2 and had the same issues in the past - the mod_jk and mod_jk2 were both debian packages installed via dselect. Thanks vahid