Virgin Media broadband subscribers have experienced further difficulty accessing video-sharing website YouTube.
A number of customers took to the Virgin Media community forum over the weekend to complain about lengthy buffering, or a complete inability to access the website.
The latest round of problems dates back to the middle of last week, but Virgin Media has struggled to get to the bottom of the issue.
Broadband users in Bristol and the south-west of England have been particularly affected.
The cause is believed to be a caching server used by Virgin Media to make YouTube loading speeds faster.
Joe Thomas, Senior PR manager at Virgin Media, told TelecomsTech the company was aware of intermittent, local issues with YouTube.
He said the service provider had been working directly with affected customers and Google to investigate and resolve issues as soon as possible.
Virgin Media has been experiencing problems with YouTube for some time, with the first reports of service outages dating back to March 2013.