BlackBerry users across the world have been left without email or text services for a second day due to an unexplained fault.
Customers in Europe, the Middle East, Africa, India, Brazil, Chile and Argentina have now reported problems with their devices.
They have been venting their fury at the lack of service on Twitter and other social networking sites.
One customer tweeted: "You realise that sending a letter in a bottle and putting it in the Thames is more reliable than a BlackBerry ."
Another joked: "What did one BlackBerry user say to the other BlackBerry user? Nothing."
The server problems are believed to stem from a data base in Slough and started on Monday morning.
However, it is not known what specifically caused the fault.
Manufacturer Research In Motion (RIM) had given the all-clear on Tuesday morning after the first problems.
But they struck again later, leaving users unable to access emails or the internet or use messaging services.
RIM said in a statement: "Some users in Europe, the Middle East and Africa, India, Brazil, Chile, and Argentina are experiencing messaging and browsing delays.
"We are working to restore normal service as quickly as possible. We apologise for any inconvenience this has caused."
Regular voice-calling services appear not to have been affected, and the problem seems to be limited to personal rather than business contracts.
Mobile operators in the UK including T Mobile and Orange posted messages on their websites referring customers experiencing difficulties to the manufacturer.
Vodafone said: "Research in Motion (RIM) is currently investigating the issue as a priority to restore services as soon as possible."
TV critic Ian Hyland tweeted: "All we need now is for i-phones to start playing up and we'll have the dream headline: 'Apple and Blackberry Crumble.