windows explorer renames files with lower case

Are you a windows user who suddenly finds one or more of your files have been mysteriously renamed using all lower-case letters?

Note, this occurred on a Windows 7 system, but I'm unsure what updates may have been installed at the time because now I can't duplicate the bug anymore. Being presently unable to reproduce this behavior also means this post won't have any screen shots (my apologies).

However, it was odd enough that I thought it deserved a quick write-up...

The basic steps were:
- Open Windows file explorer to a folder containing lots of files, in my case they were '.zip' files - Use the search box in the upper right to find a subset of the files in the folder, probably by searching on some part of the filename - Select one or more files from the search results - Drag selected files into another folder in the folder tree view or onto another folder's explorer window.

Finally, marvel at how your files have been silently renamed using all lower-case characters. Note, this all applies to network files and I don't have any details on the setup of the file server.