Nood needs HELP!

So I ran a regular, default mine craft server for about 2 days, and all my friends suggested CraftBukkit. Used the "noob installer" for CB 1.2.3. I'm using Windows Vista Home Premium 64bit and I altered the Craft Bukkit starter accordingly. I only changed one property: onlinemode=false. This did not mess up the regular server. The server-ip= (blank) so I can connect with "localhost". When I set the server-ip= (my ipv4 adress) <--used this for MC server) I doesn't let me connect. The Mincraft server list says "communication error" when I connect with localhost, I get in just fine...but my friends can't. please help me fix this.

SERVER PROPERTIES:
allow-nether=true
level-name=world
enable-query=false
allow-flight=false
server-port=25565
level-type=DEFAULT
enable-rcon=false
level-seed=glacier
server-ip=
max-build-height=256
spawn-npcs=true
white-list=true
spawn-animals=true
online-mode=false
pvp=true
difficulty=1
gamemode=0
max-players=20
spawn-monsters=true
generate-structures=true
view-distance=10
motd=A Minecraft Server

lol in title: Noob*

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

umm, its a port forward problem, or a firewall. Check it out, more in-depth.
here is a link to help you:
Youtube

 

I already know I've port-forwarded correctly because my friends could connect to the non-CraftBukkit server.

 

You need to provide more information about your server, I looked over your post closely and the only thing that comes to mind is a port forwarding issue.

Check to see if you have a new IP assigned to your computer, that would break any port forwarding rules you had working before.

 

My regular server was in-use by my friends as I was setting up the CraftBukkit one. The ip I forwarded is my ipv4 address with the port 25565. This worked fine with the regular minecraft server. I stopped the regular server, and not 5 mins later launched the CB server. I could connect with localhost but my friends could not connect with the external ip, like they used to. Please tell me if there is any more info you need. CraftBukkit seemed so nice to have.