The latest update to iOS 6, iOS 6.1, is apparently causing some major problems with Exchange Services, resulting in some corporations suspending the use of devices running iOS 6.1 on Exchange networks (via Tony Redmond and 9to5Mac). The problems apparently stem from iOS 6.1 causing excessive transaction logs for Exchange servers, apparently generation in excess of 50GB of transaction logs in some instances due to access loops for calendar meetings.
We have also been contacted by two users, one of whom works for a major University, stating that iOS 6.1 users will be banned from accessing corporate e-mail until a bug fix is issued by Apple. Interestingly, German site iFun has today reported that Apple is rushing through an update in the form of iOS 6.1.1. However, the report is suggesting that this update predominantly deals with 3G carrier issues in Europe, and it is unclear at this time if it will affect the Exchange issues.
Anecdotal reports have suggested that iOS 6.1 has contributed to excessive battery drain for some users and that this could be related to the Exchange bug. Some users are suggesting that anyone experiencing problems should delete and re-add their Exchange accounts on an iOS device.