ftp_err-COULD_NOT_CONNECT Error

Can't even start the upgrade to 4.0.5.1 from 4.0.4 because I'm getting two instances of this error on the System Check screen. Both are listed under File System Requirements. All other directories are being detected as writable. I've even double checked that all directories relevant to Community Suite are writable on the FTP server. So, I'd like a bit of help fixing this. Though, considering all the posts I've read about 4.0.5.1, I may have dodged a bullet.