That does not appear to be the issue. When I transfer the file to a Linux box (yes, my office workstation is Windows until I get time free to change that) the whole filename is lower-cased, just like on the Windows box. In fact, I checked for the same thing before, and other known Windows issues such as funky path resolution (I used the DOS six-plus-tilde-plus-number versions of the directory names and everything, to no avail).
I think I've even tried multiple browsers, but I can't recall for sure.