I have no idea what those FTP servers are or what they do. There could be other extenuating circumstances (e.g. you've already pulled X data at Y speed because of the first test, so they're throttling you on the second...)
Only other thing I can think of is you're somehow connecting to wifi (or perhaps dual-NAT?) when you're connected to the ER, and the computer uses that slower connection, rather than the wired...