Mac-PC video chat?

Greetings. I was trying to video chat with my cousin the other day, he has a Toshiba laptop running Windows XP. He uses AIM 6.9 and I use iChat. He has an external webcam and iChat couldn't see the webcam, but it could see his microphone. He invited me to a video chat and iChat said, "No response from" my cousin. I was text-chatting him just fine, it was just the video chat. I had video-chatted with him before on his same computer and my same computer. Is this a normal problem with Macs? Or is there something I need to do? Help is appreciated. Thanks in advance.

I'm also curious about video chat on iChat. I haven't gotten it to work once... even with my friend who has a Mac. I can video chat w/o a problem on Skype, which is all well and good, but I'd prefer to use iChat. Plus, only iChat allows for conference video chats.

Your best option for multi-platform video conferencing is Skype. I've used it on my Mac with friends who have PCs and it works great. Sure, it's not as fancy looking as iChat, but it gets the job done.