ok, it was norton all along. I pulled out anything to do with Vue in Nortons firewall, next time I started Vue Norton asked again if it was ok to permit Vue, and it now works. According to the programmers at Norton, some programs replace the .exe file when they update the program, if this happens Norton can see this as being different and not use the old rule for that program. But when it comes to adding the rule it finds a rule for Vue there and doesn't replace it. I don't properly understand this, but it is sorted now.