Slow Reads from Server using Windows 7 Clients

I have three Windows 7 clients on my network and I happened to discover that copying files from either of my two unRAID servers was very slow.  At times, it would even fail completely.  It was virtually impossible to open a file on either server using a Windows application by double-clicking on the file name.  What I was seeing can be seen in the attached screen capture.  Windows Explorer was hung-up for several minutes before the actual copy would begin! When the copy process finally did start it was under 1MB/second! 

I spend most of today working on the problem.  I verified that that neither server was actually running slow or that there was any real problem in the physical network.  I could stream blue-ray content via SMB to my Linux power set-top Media Boxes without any issues from either server. 

I googled the problem and found that this was any issue early in the life of Windows 7 and that witchcraft was usual method of solution.    Then the problem apparently disappeared...  I suspect that MS made some change to the Windows Explorer that fixed the problem. 

I even tried uninstalling the most recent updates from MS (I know the problem started some time the past month or so.) That didn't work.

I strongly suspected that the problem was related to Windows Explorer.  I searched for replacements for that application.  I found a few possibilities and narrowed down the field to two---  ExplorerPlusPlus and FreeCommander.  Both of them are free and seemed to have reasonable reviews.  I looked at the websites for both of them and decided to ExplorerPlusPlus first.  The reason for this choice is that I didn't have to install it.  You just double-click on its .exe file after you unzip it and it works.  The use of it solved the problem of copying from and application file loading from either server. 

One important observation which I forgot when I prepared the initial posting.  There was never a detectable slowdown in uploading files to either server.  The problem was confined to downloading.  The problem existed whether I used Windows Explorer to access the share from 'Network' or mapped the share as a drive. 

Thanks for the tip, but my issue is not related to Windows explorer. It even exists locally on the server.

I am 99% sure it's related to the magic that presents multiple drivers as one as it only exists on user shares and not directly on the disks.