Bukkit Server Problem!

Please read my blog post! It includes the picture and everything!!
PLEASE PLEASE NEED HELP!!!

http://www.planetminecraft.com/blog/buk ... need-help/
http://www.planetminecraft.com/blog/buk ... need-help/
http://www.planetminecraft.com/blog/buk ... need-help/
http://www.planetminecraft.com/blog/buk ... need-help/

I am currently having a lot of problems with my Bukkit Server I recently put up. I had tons of people joining and in a matter of seconds the server was full, but thats when the problem began. When people spawn at the spawn, they're stuck! No one can move, and no one talks, then they look connection after like 15 minutes. The picture above is what my server console keeps spamming! Please help
Why does it keep doing this?
I'm running my server off my computer and own internet. (I have a very fast and good internet connection) I wasn't downloading anything while the server was running, etc.
Why is this happening? Why didn't it happened at the beginning when I first put up my server?
(This happened about 20 minutes after putting the server up, it was running fine until then)