I have had that happen, most commonly when the subject line is too long in the original posting. If I use the browsers forward and back buttons, I can lose what I have typed. I know that can be frustrating. For that reason, I have on occassion taken to typing out longer responses in a text editor, and then pasting them into the comment window. That way, if it does dissappear into that giant vacuum of the internet somewhere, or wherever that place is that one half of my socks and gloves end up, I have a copy to paste in. Rich