A zone crash would kick all clients.
Smart Trades:
www.eqemulator.org/forums/showthread.php?t=38675
I'll take a look through the code to see what conditions might cause this..but, I haven't heard of any issues since the last post
in that thread.
Post some examples of your stacksize changes (before -> after)
Did you re-run shared_memory.exe after making these changes?