Error when using Export-Mail CMDLET

Hello Experts:

I am using Exchange 2007 server with SP1.  When I use the command Export-mailbox -id usermailbox  -TargetFolder 'ExportedData' -TargetMailbox usermailbox2 and supply the correct name of the user mail box and the Target Mailbox--all goes well until the last step and I get the following message:

Error occurred in the step: Creating target
folder in the target mailbox. An unknown err
or has occurred.

Could someone tell me what I am doing wrong?

Thanks

You need to be sure that you have Full Access to your TargetMailbox
If your are using the following cmdlet it would be usermaibox2

Export-mailbox -id usermailbox  -TargetFolder 'ExportedData' -TargetMailbox usermailbox2


Manage Full Access Permission from In the Exchange Management Console.
"Recipient Configuration" > "Mailbox" > Right-Click "usermailbox2" > "Manage Full Access Permission..."
Click "Add...", Select "DOMAIN\Enterprise Admins" > OK > "Manage" > "Finish"

Try and execute Export-CMDLET again.  It worked for me...