Can you send Jpeg to person A. but not pcx to person A. ?
Or is it that you're sending Jpeg To person A. And pcx to Person B. ?
If so then ask him/her if they are using a firewall (or it might be the ISP's local network that has some sort of Firewall).
I can't think of anything else you can do since I don't much use MSN for sending/recieaving files
