Pulse update not working over a proxy NIS 2011

I have 7 Windows XP pro SP3 machines on a wired network.

I have Norton NIS 2010 on each machine and I am currently udating them all to NIS 2011.

I use a proxy server program to allow 6 machines to use 1 internet connection.

When I updated the server, which has the modem connected to it, the pulse update works

correctly udating every few minutes. On the machines which use the proxy settings the

pulse update does not work at all. However, If I click on run live update manually the program

connects and downloads the patterns etc. When the program was first installed it correctly

read the proxy IP address and port number and asked for it to be confirmed. When the program

checked for activation it also connected correctly and activated ok. It is the same settings used

by Internet explorer which works correctly over the proxy. NIS 2010 had the same problem.

Does anybody know why pulse would not be working correctly over a proxy?