We have identified an issue with the new NDIS6 compatible TAP driver that is being installed with the latest version of OpenVPN. The issue causes very slow DNS resolution through the VPN service, which makes it so that pages take a very long time to load, or fail to load completely.
The NDIS6 TAP driver is bundled with the "I006" versions of OpenVPN. The driver was updated to fix some long-standing stability issues with Windows 8 and Windows 8.1.
If you are having this issue in Windows Vista, 7, or 8, we recommend that you uninstall the I006 version and install the I003 version that contains the older TAP drivers. This appears to fully resolve the issue.
As was the case before, if you are using the I003 version of the TAP driver with Windows 8 or 8.1, you have to be extremely careful and restart your machine before each time you sign on to the service. This is because Windows improperly handles the older TAP driver and it enters an error state where it doesn't initialize properly.
This issue with the I003 version does not occur in Windows XP, Vista, or 7.