Exchange Server 2010 EMC Initialization failed because the user was not found it was running 'Get-logonuser'

I have found the following resolution:

"This usually happens in Hyper-V or another Virtualization software, when the same Image that was created is used without Sysprep, EMC will not start if the Machine SID conflicts with Virtual Machine or Host.
To sysprep try to go to c:\windows\system32\sysprep, and make sure you check GENRALIZE."

http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/375cf88d-4879-4dc9-a522-bcbf6bedc1b0/

VERY IMPORTANT! Run sysprep on clean OS, before installing Exchange.

My scenario:
Install Exchange 2010 SP1 Hub Transport Role and Client Access Role on one machine and Exchange 2010 SP1 Mailbox Role on a different machine. I was using the same 2008 R2 base image. After installing Mailbox Role on the second machine, the Exchange Management console would fail to initialize. So I started from the begining:
- installed Hub Transport and CAS roles one the first machine;
- run sysprep on the clean OS for the second machine;
- installed Mailbox role on the second machine;

=> and no error :)