I saw this before and as far as I know, Microsoft considers this a COSMETIC defect and as they are focused on Windows 8 plus this is not a fatal flaw you should count of no fix from them.
As we read http://superuser.com/questions/266110/how-do-you-make-windows-7-fully-case-sensitive-with-respect-to-the-filesystem we learn that MSFT took the sloppy approach to file names. If you don't remember why, that's OK because why is from over a decade ago.
I really hope I've come to the right place, because I'm at my wit's end with this. OK, here goes:
I've got quite a few mp3 files stored on my PC's hard drive, and I've got them all sorted by Artist---Album---Track. If I open a particular album in windows explorer (Windows 7), I have all the tracks for that album listed along with the details. In the individual album folders, they all look the way I want them to look, particularly with capitalized first letters. Now, when I go back to the artist folder where all the albums are listed, I type "mp3" in the top right search bar. When I do this, all of the mp3's I have stored for that artist show up, again, with the details. However, in this view, a good portion of the mp3's are all in lower case, which is not how they are in the individual album folders. In the overall view with all the mp3's for the artist, I attempt to change the title (both with the rename tool and by clicking on properties) to reflect the capitalized letters. However, as soon as I click OK or Apply, it shows the corrected name, but then immediately reverts back to all small lettering. How can it be different for the same mp3 files in 2 different folder views? This is driving me nuts!