Strange IE 9 behavior when using “Automatically detect setting” and a Proxy.pac that is promoted through DHCP.
When starting IE, intranet sites are working from the beginning, but internet sites are only working after opening Internet Options –> Connections –> Lan Settings, and then confirming with “OK”. No changes have to be made in the settings, it’s just about opening them, and closing again. This issue is reproducible every time the user profile is deleted.
After some further investigation with Procmon it was clear that settings are written to the registry, even if no changes are made when open the Lan Settings dialogue. The important ones are:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings] "EnableAutodial"=dword:00000000 "NoNetAutodial"=dword:00000000
Setting these 2 values using a script, or in our case GPO’s will solve the issue.