ECS 915P-A ddr2 533 ram issues

Hello, I've decided I want to upgrade my desktop with more ram. I purchased a 2 gig set of ram( Kingston DDR2 533) which is suppose to be compatible with my mobo. I currently have 2x 512( CORSAIR/VALUE SELECT DDR 400) ram running with this machine with no problems i believe. Now, when i decide to swap out the ram with the new one(i.e Taking out DDR 400 to put in DDR2 533), the ram fits, like how its suppose to... but when i start my comp, it just stays as a black screen..., I hope i can get some ideas... cause i really have no clue, hopefully someone can help... it might be a hardware power issue, by not being able to read ram slots 2, and 4 but i have no idea


*A few things about my mobo that should(or help) be noted
It has 4 ram slots, 2 meant for ddr, the other two meant for ddr2
Cant have both running at the same time.
running windows xp
when i run cpu-z in says my bios is dated 08/08/2005, and I cant find anything later then that as an update

*UPDATE* im running an ECS915-A mobo Chipset Intel 915P/915G
I dont believe I caused a static charge... whether the case i was grounded or not(I touched a metal screw), I handled the same ram that is working in my machine currently right after (DDR 400 2x512)
i am "trying" to run dual channel of 2x 1gig ddr2 533(which means two 1 gig sticks) just in case

Is the Kingston part number KVR533D2N4K2/2G? If so, it should work if you have a version 1.1 or newer ECS915-A motherboard.

Try one module at a time. Make sure the slots aren't filled with dust or lint. If need be, vacuum them, but be careful.