Hi. I have a Chaintech 7NJL1 Motherboard, running 2X256 DDR400 RAM in Dual Channel, with Win XP SP1. I have just purchased a 512MB DDR400 Twinmos RAM Module and installed it, but now my system has become totally unstable, giving blue screen shutdowns with causes ranging from nftc.sys, win32.sys to 'irql_not_equal'. I have removed the stick & reinstalled it with the same problems. Now I have removed it completely there are no probs at all. Can anyone help me with this?