BASH History

Hi, The BASH history question reminded of a small problem I have with this function that perhaps someone can help me with. I always keep a Konsole window open in which I have four regular interactive BASH shells and one root shell running. When I log out or shut down, it seems that the four shells running under my user ID clash somehow or fail to coordinate in the way they write the history file, and I end up with only one of those shells' history. Does anyone know of a way to get all four shells' worth of history saved? Randall Schulz