You might want to read this thread before you put a BigRAM or ZorRAM in your A4000.
http://eab.abime.net/showthread.php?t=67514
Ug.. glad he figured it out..but what a struggle to read through. Just me but I always throughly inspect hardware/chips caps etc..before panic mode..lol
Interested in this thread as I have just found out about ZorRAM and was thinking about it for my machines.