550 Failed to change directory.

I've looked quite a bit to find a solution to this problem but I can't find anything that can fix this.

I've installed LAMP and I have a server up and running.

But when I try to install SMF, I'm given the option to have the install script change the chmod of folders so that they are writable. I enter in all of the appropriate FTP information and I get a 550.

I've been told it's a permissions problem but I don't see how because I've chown the directories to the user I log in with and most of the files and directories are chmod 755

Also, I can't seem to delete files when I log in FTP.

Thanks in advanced whoever can help me solve this problem.