iChat buddy disappears

Hello everyone. I'm having a little problem with iChat. I'm running Leopard, and the latest iChat. All the updates are in, and it works like a charm. I can't add a buddy to my buddy list. He's logged on, and he's in my address book too.

I invited him, and he shows up in my buddy list for a few seconds, then disappears. Help please? I googled and searched this site, but no avail. I can still chat with him in the window, but he doesn't show up in my list.
I just added another buddy, which worked. Apparently it's just him.

Anybody? I tried it on my uncle's ibook. He shows up. Help would be appreciated.

Add buddy to iChat, quickly disappears

Same issue that you are reporting. Sorry to say that I don't have a solution. I have two laptops, both running Leopard (MBPro and MB). Both originally had the issue, but the MB displayed about 5 mins after we added the buddy. MBP still hasn't shown. I can add and readd the new buddy, but it will quickly disappear.

The buddy is using AIM (both my laptops are using iChat) and the buddy can see us just fine.

I don't know if you two are still looking for a solution to this or not, but I found a successful answer here:

http://kamran.kazempour.ca/blog/2007/12/27/cant-add-a-ichat-buddy-name-disappears-after-5-sec/