Yup, you are right Jack. For some reason, techsupport tried to disable the firewall of the antivirus, but it didn't work. I guess it takes a while for the setting to kick in. I also had to search as some of the computers had windows firewall also running. They both had to be disabled.
I don't know why it takes time for the settings to work. I think some residual function of the firewall is there, and does not clear up until the computers are rebooted.
The memory issue appear to be a non issue, as now even the terminals with only 256K runs fine.