Symantec's Norton security software began cutting AOL users from the internet last week after a faulty security update judged that AOL traffic was malicious.
The problem started on 15 March when a rogue intrusion detection signature file was sent to users via the company’s automatic LiveUpdate service.
The problem affected both dial-up and broadband customers using AOL to connect to the internet.
Symantec said it discovered the problem and then sent out a new signature file to fix the problem. However, as affected users were cut off from the internet as a result of the problem, most of them weren’t able to access the fix.
AOL, which is one of the UK’s main dial-up ISPs and a leading broadband provider, is said to have received thousands of customer calls from stranded customers.
Last week, McAfee distributed a rogue security update that quarantined or deleted the Microsoft Excel spreadsheet application and a host of other legitimate programs.