psexec always access denied when send Windows 7

I have Access denied message when trying to run cmd remotely from system user account.
The scenario:

Im logged on win 2008 Std machine. Domain user has local admin privileges.
I can run cmd.exe on remote machine (windows 2008 Ent) in system account.

C:\Users\Domain_User>psexec \\remotehost /s c:\windows\system32\cmd.exe

PsExec v1.98 - Execute processes remotely
Copyright (C) 2001-2010 Mark Russinovich
Sysinternals - www.sysinternals.com

Microsoft Windows [Version 6.0.6002]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Windows\system32>exit
c:\windows\system32\cmd.exe exited on remote_host with error code 0.

All is ok. It is working fine with domain user with admin privileges on remotehost machine also.

Then I run cmd locally in system account and try to run cmd remotely under domain user account (domain user has admin privileges on remotehost)

C:\Users\Domain_User>psexec \\localhost /s c:\windows\system32\cmd.exe

PsExec v1.96 - Execute processes remotely
Copyright (C) 2001-2010 Mark Russinovich
Sysinternals - www.sysinternals.com

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Windows\system32>psexec \\remotehost -u DOMAIN\Domain_User -p pwd c:\windows\system32\cmd.exe

PsExec v1.98 - Execute processes remotely
Copyright (C) 2001-2009 Mark Russinovich
Sysinternals - www.sysinternals.com

Access is denied.
Could not start PsExec service on remotehost:

C:\Windows\system32>exit
c:\windows\system32\cmd.exe exited on localhost with error code 122.

What is wrong. On both systems UAC is disabled, fw is disabled. From win 2003 this scenario ends without any errors.

I'm using psexec to install software remotely from windows service.