Interactive Chat

I am looking to use "ChatLive" with my 4/5 graders.  Is there anyone who has used this with success?  I have my username and password ready to go.  I placed the link on my classroom website, but when the kids tried to access it.......it failed.  I even gave them my name and password and still nothing.  It was active and working. 

Any ideas or suggestions in using this would be welcomed.

Thank you!