Well,this is my first post:

Does anyone know if there is any research being done at the various academic institutions or anywhere else on the use of AI and Neural Networks for detecting intruders on a Computer Network ? If there is, can anyone point out links to these works cause I would very much be interested.

I imagine there is, although I don't have any specific resources handy. You might consider looking into artifical immune systems, which are generally used to detect novelty or anomalies. They have been used for this application and there is a fair amount of free material on them, as well several books, such as, "Artificial Immune Systems and Their Applications", edited by Dipankar Dasgupta. You'll find the ISBN in Will's Technical Book List, availible at:

http://will.dwinnell.com/will/willTechnicalPublications.html