Some TalkTalk connected lines dropped at around 14:14. They are reconnecting now though. We'll investigate and will update this post.
This looked like it was a wider TalkTalk problem as other ISPs were also affected. Most lines are back online now though. We will investigate further.
TalkTalk have been contacted and a Reason for Outage has been requested.
TalkTalk have confirmed the outage on their status page: http://solutions.opal.co.uk/network-status-report.php?reportid=3893
Update from TalkTalk: 15:59 24/04/2014 Supplier has noticed a link flap between two exchanges which resulted in brief loss of service for some DSL customers. The traffic was reconverged over alternative links. Supplier is still investigating for the root cause.
Incident was due to a transmission failure which the supplier is investigating with the switch vendor. We've also had this update from TalkTalk: The cause was identified as a blown rectifier.