WhiteBlaze automatically logs a user off after 15 minutes of inactivity. Typing a message or replying to a message that takes more than 15 minutes does not show activity because the page is stagnant. We have to set some type of time limit, otherwise it would show you logged in 24 hours a day if we did not have a limit.
If you log in using the check mark in the block "Remember Me" and have cookies enabled on your computer you will not run into this problem.
If you do not want to use the Remember Me block or use cookies and know that your going to type a message that will take more than 15 minutes you could avoid this problem by having two browser windows open in WhiteBlaze. Have one browser window opened to the Who's Online window, this automatically refreshes every 60 seconds and by doing this it will not log you out. Without closing this Who's Online window you can go to the second window and start typing the message that you think will take more then 15 minutes to type in the second window.