It's a problem with the setting of the "If a file already exists" menu in the Put dialog in Fetch. Here's a link to the FAQ entry:
And here's the text:
- After I upload my files, they do not have their correct names, instead the names are either gibberish (such as "ftpBYTlvT") or have ".1" after them.
When you use the Put command, do not set the "If a file already exists:" menu to Pick a different name in the Put dialog. Instead, set it to Replace existing file.
When this menu is set to Pick a different name, Fetch asks the server to pick a new name for your files if ones with the same name already exist, so that your existing files are not replaced. Unfortunately, some servers pick names that have little relation to the file's original name.