I am using an encrypted (Truecrypt) data-Partition (fat32), on which my Dropbox folder is located. This Partition is mounted on Windows 8 as well as Crunchbang (Debian wheezy) and Ubuntu 12.10. When it has mounted, Dropbox starts to synchronize the folder (in principle on every OS, but currently only Crunchbang is configured for Dropbox).
Now when I save a file or create a directory with a special character (umlauts in particular), then this file/folder will be renamed - three times, creating three items with the same content, but different names.
This only happens inside the Dropbox directory, every other directory works fine. Since I am german, it is impractical to avoid special characters (especially umlauts), most of all winside shared dropbox folders, because then I'd have to ask everyone to avoid those characters too.