This issue used to be reported fairly frequently, but not recently. Have you got a checkmark against Network Time Protocol in the firewall section in Security Center which really shouldn't be necessary as system services are silently allowed by McAfee?
There was also an issue in Vista with network time not synching but that was supposed to have been dealt with ages ago - make sure Vista is up to date with all updates whether critical or not. Have you tried using a different time server when you call up the System Clock?
Also make sure that you don't have Windows Firewall turned on, or any other firewall for that matter.
Also advise if you are behind a proxy....such as those found in Universities.
A proxy is, as I already stated, something you would find in a University or some businesses where they have a firewall blocking everything.
Double-click the taskbar icon to open Security Center Click Advanced Menu (bottom left) Click Configure (left) Click Internet & Network (top left) Click Advanced (right) Click System Services (left) Check the item "Network Time Protocol (port 123) Click Apply and OK.
Are you behind any other firewall?????
What is your operating system and service pack and what other protection software do you have?
I removed McAfee and still have the problem, so McAfee is eliminated. (I have since reinstalled and did what you said to do about port123). I am using VISA Home premium Service pack 1 with the latest updates.