So I was chatting to a guy for ages this evening. Then I momentarily left the web page and when i came back all his messages were gone from my mail box. I also looked up his username and it says error.

My only guess is that his profile was suddenly deleted but I have not idea why that could be.

odd...FB you've ruined it for me.

Well maybe he was deleted for not confirming his e mail address, annoying other users or maybe he got tired of the site and deleted his profile himself.