Why is my iChat not working?

Why do Airport, iChat and VPN stop working in certain coffee shops? I've been working remotely this week for the first time, and I keep getting suddenly disconnected. Sometimes when I walk in the shop and open my Macbook, the Airport logo is greyed out...

I made an ichat account with AIM, and I can't add a buddy. Or when I do, that person will never get the request. If somebody tried to add me, I need get the request. I do not now what's wrong, help?

I've had a mac book for awhile and my ichat has always worked just fine. One day it just decided not to work and I haven't been able to get it to since then. I can log on and see that my friends are online, but when I try to click on them to talk to...

Every time i log in to iChat, a second later it logs me off, and a pop up comes up that says "Disconnected from iChat Agent" and then under that it says, "The iChat agent has unexpectedly quit, disconnecting you from all services. Logging...

I have an internet connection, of course, but when I try connecting to iChat, it won't! What do I do?

Some how my ichat got deleted. I've gone too my app folder and clicked it but a little box pops up and its blank that says "No iChats" help!?

i have an mac pro. i use ichat. whenever i try and video chat, it either says “error” or blank declined your request, when they didnt or i can see my video but my friend sees a black screen help!!!!!!

I use AIM and i can send regular messages but when i try to send a video message to another mac it says its connecting but it never does? I have a mac and have never used it