550 Rename: Not a directory

[otherwise]

whenever i try to name a drirectory "images" in the main directrory i get this error "550 Rename: Not a directory" and it forbids me to do so.
any idea?


when i try renaming i get this:

50 Opening ASCII mode data connection for file list
226 Transfer complete.
Transferred 1,447 bytes in 0.008 seconds
RNFR /mages
350 File or directory exists, ready for destination name.
RNTO /images
550 Rename: Not a directory

thanks in advanced