The ActiveSyncDevice cannot be found.

In Active Directory Users and Computers, I selected the "Users, Contacts, Groups, and Computers as containers" option on the view menu, and I navigated to a user's "ExchangeActiveSyncDevices" folder, and I manually deleted each of the devices.

Now, I'm trying to remove the partnerships using EMC, but each time I try to remove one of the partnerships I get the message below:

Summary: 1 item(s). 0 succeeded, 1 failed.
Elapsed time: 00:00:00

(User Name)\Apple-iPad2C3/812.1
Failed

Error:
The ActiveSyncDevice DOMAIN.LOCAL/USERS/User Name/ExchangeActiveSyncDevices/iPad§Appl... cannot be found.
Click here for help... http://technet.microsoft.com/en-US/library/ms.exch.err.default(EXCHG.141).aspx?v=14.1.267.0&t=exchgf1&e=ms.exch.err.Ex0FBD0C

Exchange Management Shell command attempted:
Remove-ActiveSyncDevice -Identity 'DOMAIN.LOCAL/USERS/User Name/ExchangeActiveSyncDevices/iPad§Appl...'

Elapsed Time: 00:00:00

I am able to remove partnerships from other devices without any problems, so I do not believe this is a permissions issue. I'm pretty sure part of the problem is that I've already manually removed the device from AD and this is causing the error in Exchange.  I have have tried to use PowerShell and Remove-ActiveSyncDevice, but this generates a similar error.

How can I remove the partnership in Exchange?