Sky Broadband is fixing an error that has been blocking UK customers from accessing and using the PlayStation Network between 5pm and midnight.
The system mistakenly classified PSN as a traffic-heavy application, and therefore sought to prevent or block connections to it during peak hours. Fixing this is a matter of priority, Sky says.
"Our network management system mistakenly classified PlayStation 3 traffic in a way which meant some customers using their consoles to access the internet may have had their speeds reduced, in line with our network management policy for Sky Broadband Connect," Sky told our sister site Eurogamer in a statement.
"This was a mistake and resulted from a systems error, for which we apologise. Our team is working on fixing this as a matter of urgency. All other Sky Broadband users are unaffected, as there are no traffic management policies in place for our on-network broadband services."
Traffic management, Sky went on to say, only applies to Sky Broadband Connect users using peer-to-peer applications.
"There are no restrictions in place for applications such as web browsing, email, video and audio streaming, instant messaging and VOIP during peak times. And we do not put restrictions on our network outside of peak times (5pm to midnight)," added the company.
European PlayStation forum users reported the first problems late last week. Some users have spent entire evenings signed out of the PlayStation 3 online service.