One of our users, who has a large number of contacts in her personal Contacts folder, recently bought a Windows Mobile device. We're having trouble making Exchange ActiveSync (EAS) synchronize the user's contacts to the device, which is reporting a DEV_10 error. What does this error mean, and how can we fix the problem?

Any error that starts with DEV_ is a device-side error. In this case, DEV_10 indicates that the device timed out during the synchronization. EAS batches updates in groups of 100, so check the device to see whether any items have been synchronized. If nothing at all appears on the device, try increasing the EAS timeout value. If some contacts appear but the synchronization fails before all the contacts are synchronized, you probably need to use the NexTags utility to turn up the logging level so that you can isolate the source of the problem. (The Microsoft article "How To Troubleshoot Server ActiveSync," at http://support.microsoft.com/?kbid=330461, describes how to use NexTags.)