The file list includes other information besides the file name, and the Get File button doesn't work. Otherwise you can hold down the option key when you press the Get File button and type in the file's name by hand. Your network administrator can resolve this problem by assigning names to those addresses. Fetch does not capitalize the command, the server does. In fact capitalization of FTP commands does not matter.
Fetch sometimes guesses what kind of computer it is talking to, and it can guess incorrectly.
The files I get don't have the right icon. This problem can be caused by a number of factors. If you are using System 4.2 and Finder 6.0 you should upgrade since that system version has a bug that causes files to lose their icons. If you use MultiFinder you should try saving the file to a folder that is not currently open in the Finder. Also, check with your network administrator to see whether you are separated from the Internet by a firewall.