Windows 7 Explorer Hangs Interminably On Network Copy to 2008 R2 Server

Quick Description:  Windows explorer hangs copying large files at “discovering” and never returns when copying from Windows 7 to a Windows 2008 R2 network location.  Attempting to cancel, or close the dialog will switch the dialog to say it is copying with n minutes left, but no progress is actually made.
Solution:  As referenced in KB951037 disabling TCP Chimney Offload instantly solved the problem for me.
From an administrator command prompt type:
netsh int tcp set global chimney=disabled

Update:  This can also a problem with Symantec Enterprise Protection 11.  My feelings about the product notwithstanding, many company domain policies will allow you temporarily kill the service (services.msc) while you perform a specific task.