YouTube: Finally fixed slow loading during peak hours and some videos don't load at all

For months I've been wondering why the hell my YouTube kept buffering during peak hours.

At first I thought it was my ISP oversubscribing users on high data plans, but it was during the peak periods so that didn't quite make sense. (Australia doesn't quite have truly unlimited internet plans yet.)

So after contacting my ISP and getting some generic responses back like:

• Check your firewall
• Antivirus subscription
• Windows Updates
• No Peer 2 Peer programs running
• Speedtest on another computer
• Isolation test (unplug all telephony devices except for router/modem)

I didn't bother with trying out another modem, because it had been working fine the whole time and the problem was only during certain hours of the day.

Eventually I figured it out. For some time now I had configured my router to use OpenDNS. At first it was not an issue, but I guess something changed and it couldn't cope with the stress.

Disabling the use of OpenDNS and reverting back to the DNS hosts provided by the ISP worked wonders. Once again the videos stream without buffering.

Disable OpenDNS Guides (Automated search)

If you're like me and tend to get lazy with typing the whole URL in your Firefox browser so it just takes you to the first result automatically, you'd notice that OpenDNS has overridden that feature by default.

Instead of letting Firefox take you to the Google search page, it will take you to an OpenDNS Guides page such as http://guide.opendns.com/?url=search+query

To disable this, open up the OpenDNS dashboard to configure the advanced settings.
Untick everything on this page and it will work, although I believe the main culprit is "Enable OpenDNS proxy".

I still have "Enable stats and logs" enabled, but unsure whether this still works or not.