QUOTE(XBMC FAQ @ Oct 18 2006, 05:00 PM)
The Xbox built-in harddrive is formated in FATX which has a 4GB file-size limitation, and only supports file/folder-names up to 42 characters, a maximum of 255 in total file-structure character-deept and a maximum number of 4096 files/folders in a single subfolder, plus in the root of each partition the maximum number of files/folders is 256. FATX does not either support all ACSII characters in file/folder names (like for example < > = ? : ; " * + , / \ | ¤ &).
See if your files violates one or more of these FATX limitations, 740MB of mod is a lot of stuff.