Voici en anglais les causes les plus probables:
Solution:
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Before you begin: This issue has been fixed for NIS and NPF 2002 with the latest LiveUpdate patch. For details on how to apply the LiveUpdate patch and what was fixed, see the Information on versions and patches for Norton Internet Security and Norton Personal Firewall document.
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There are other causes of this problem for other versions of NIS and NPF. This problem may be due to a General rule blocking access to secure sites, or a Privacy Control setting blocking Confidential information or blocking logon information, or access to secure (https) sites is disabled. Try the following procedures in order the order given in order to resolve the problem.
To check the General rule
Open NIS or NPF.
Open the list of General Rules.
For NIS or NPF 2003 and 2004:
Double-click Personal Firewall.
Click the Advanced tab, and the click General Rules. You see the list of General Rules.
For NIS or NPF 2001 and 2002:
Click Personal Firewall, and then click Internet Access Control.
Click Configure, and then choose System-wide Settings. You see the list of General rules.
Scroll down the list until you find the rule "Block access to secure sites."
Remove the check mark by clicking on the box.
Click OK.
Open your browser, and then try to connect again.
If the issue continues, try the following steps.
To ensure you can connect to a secure site
Open NIS or NPF.
Click Privacy Control.
If using NIS , NIS Professional, or NPF 2003 or 2004, click Configure.
Click Custom Level.
Ensure that the option "Enable Secure Connection" is checked.
Click OK.
Close your browser.
Close NIS or NPF.
Open your browser, and then try to connect again.
Bref cela est du principalement a un firewall capricieux.
Le technet de microsoft (centre technique) abonde dans le même sens.