Apple said it is working to fix a bug that causes iOS 6.1 devices to generate excessive amounts of communication with Microsoft Exchange severs.
Both Apple and Microsoft are reporting that the bug causes unnecessary CPU usage and network activity. Until Apple fixes the problem Microsoft recommends blocking iPhone users from using Exchange servers.
"You may notice increased network activity or reduced battery life on the iOS device," wrote Apple in a support document on the issue.
"This extra network activity will be shown in the logs on Exchange Server and it may lead to the server blocking the iOS device. This can occur with iOS 6.1 and Microsoft Exchange 2010 SP1 or later, or Microsoft Exchange [Office365]."
The bug comes from a recurring issue with Exchange's calendar events. If a user responds to an exception error in Exchange's calendar their iOS device will continue to send out data to servers without a prompt to stop the action.
Microsoft found the issue soon after the release of iOS 6.1. Redmond offers a variety of fixes to the problem. The most drastic fix calls for IT administrators to block iOS devices from connecting to Exchange servers.
Apple says it should be able to fix the issue soon. In its support document the company says it has identified the problem and is currently working on a fix.
The bug adds to a slew of issue caused by the 6.1 update. Vodafone recently urged iPhone 4S users to avoid the release because of a connectivity bug.
Apple was able to update the issue soon after the complaint was filed.