I'm afraid they wont be no.
This is the maximum your motherboard will handle:
4x 184 Pin DDR, Dual Channel DDR 200/333/400, up to 4 GB
DDR 400, is in other words, PC 3200 speed, and so yours won't support DDR2, and in that case, won't support PC-4200 speed RAM.
With RAM though, your computer will tend to slow the RAM down if its too fast for it (no point though, as its not worth spending more for faster ram for it to be slowed down, and risky compatability issues)
In this case though, your RAM is also of a different DDR rating, and is the second version up, so I have a feeling it wouldn't work anyway.
So get PC 3200 instead or DDR 400