Victor,
Some thoughts:
1. Are you running the latest version of Rick's wwIPstuff? He updates this product pretty regularly and each update yields a more robust FTP implementation.
2. If your FTP server is Linux or Unix based, file names will be case sensitive. If this is your situation - make sure your file names match exactly! Craig's response implied you might be running Windows 2003 (I can't remember if your original post said that) - if this is true, then this comment won't apply as Windows systems are not case sensitive.
3. Have you posted on Rick's user forums at
www.west-wind.com? You may be get a faster response on Rick's product specific forums than in this general purpose forum. Rick's user forums also include access to his full archive of forum messages. Perhaps searching Rick's archives might reveal a solution?
Malcolm