All those Tecras come with DDR333. CL2 DDR333 is pretty hard to find; I'd guarantee your laptop comes with CL2.5 or CL3.
So, let's say your laptop has CL2.5 DDR333. Adding DDR400 memory is useless because it will run at DDR333. Adding CL2 memory is useless because it will run at CL2.5.
I don't think the chipset on those things is even capable of running the memory at DDR400.