Sony has urged PlayStation 3 owners to be patient as they attempt to reset their PlayStation Network passwords.
Last night Sony turned PSN online in the UK and across selected European countries, enabling online gaming after 25 days of outage.
But before gamers can get their game on online they need to download new firmware and reset their passwords. While many were able to do so without issue, some have reported receiving error codes, and some are yet to receive the required email.
According to Sony, these problems are the result of stress on the system.
"With the huge number of people coming back online at the same time and resetting their passwords, it is creating significant email traffic to ISPs," Sony said in a statement issued on the European PlayStation Blog.
"The consequence is that some of the ISPs are throttling the emails.
"We are currently trying to resolve this, but in the meantime please be patient and refrain from submitting multiple requests. You will receive your reset email and be able to get back to enjoying your online gaming."
So heavy was the password reset load last night that Sony turned off PSN services for about half an hour to clear the queue.
Online gaming is part of the first phase of the full restoration of PSN services. Other available services include the playback of rented videos, Music Unlimited, PlayStation Home,access to third party services, friends lists, chat functionality and trophy comparisons.
Some services, however, are still unavailable. The PlayStation Store is still undergoing maintenance.