Dyndns IP won't work?

I had recently purchased a server from a new host, and changed it to the IP given to me, but the IP from Dyndns I'm trying to make work won't connect.

I'm fairly certain I'm doing it the same way I had before to get it work, but I'm not sure why it isn't.

For clarification: I do NOT run the server from my own computer, I run through a host that I rent from.