How to fix gray files in Finder? Is there any way to force Finder to refresh its in-use information for gray (inaccessible) files?

Details:  

I move infrequently used files from my Mac (OS X 10.6) to a Windows Server 2008 file server.  I have recently found a large number of files which OS X's Finder shows as gray (like it would if the file was in the process of being copied).  The files in question are all valid and complete: no corruption or missing data; in fact, I can access the files from Terminal or from a Windows computer without problem, but Finder still thinks they should be considered inaccessible.

I can "fix" the problem by copying the original file to a new name, deleting the original file, waiting a minutes or so, and then renaming the new file to the original name (if I don't wait long enough, the new file will become gray when it is renamed to the original name).

Basically, it seems as if the Finder has failed to clear some "in-use" or "incomplete" flag [conjecture].

So, back to the original question: how can this be fixed?  Ideally, I would like to be able to scan the network drives and find and fix all the gray files via Terminal or Recursive operation, so I can fix them all without wasting a lot of time.
This solved it for me!  http://macadmins.psu.edu/news/2011/06/grayed_out_finder_folder 


  So, what happened? It appears that the folder's creation date was set
  to a random date in 1943.  While we are unsure of how it happened, we
  did figure out how to fix it. 
  
  We used a few binaries that came with the Developer Tools, GetFileInfo
  and SetFile. GetFileInfo showed us the creation date of the folder. We
  overlooked it at first, but with closer examination it caught our eye.
  
  $ GetFileInfo Test/ directory: "/Users/user/Desktop/Test" attributes:
  avbstclinmedz created: 06/13/1943 06:13:00 modified: 06/13/2011
  15:07:33
  
  We then could change the creation date using the SetFile tool.
  
  $ SetFile -d 06/13/2011 Test/
  
  After seting the date back to a reasonable time, we can see that it
  has truly changed.
  
  $ GetFileInfo Test/ directory: "/Users/userid/Desktop/Test"
  attributes: avbstclinmedz created: 06/13/2011 06:13:00 modified:
  06/13/2011 15:07:33
  
  The folder then showed properly in the Finder and was again usable. We
  also found that if you created an alias of the folder, you could see
  the data and move it out. Once it was moved out into another folder,
  the old folder could be deleted.