Asus A8N SLi Delux-Memory reading problem

[Psycho Pigeon]

So I thought I would add some more juice by buying a 1GB moduel. It arrived today and I have 4 memory slots. So I put the 1GB in one of the black slots as the 2 blue slots have sticks of 512 in them. But what seems to be happening is when I put the 1GB in any slot my motherboard is only recognising whatever's in the first blue slot so it even discards the other stick of 512. I've been reading the manuel and it doesn't have the 1GB modeul listed in the supported section but I think that's because Corsair didn't release the value 1gb stick then. So later I tried other setups and managed to get it to recognise upto 1.5GB so obviously a 512 stick isn't being recognised. I've tried the 1GB stick on it's own to make sure it wasn't faulty and it was fine. It brings me to the conclusion that the dual channel memory setting is getting in the way but I can't find where to turn it off, there's nothing in the BIOS that mentions it. The 1GB module is the same speed as the sticks of 512 so they are basicly the same.


I bought:

Corsair (VS1GB400C3) 1024MB, DDR400 / PC3200, non-ECC, 184 DIMM, unbuffered, CL3, 64Mx8 DRAMs

And on the Asus site it says it supports:


- 4 x 184-pin DIMM Sockets support max. 4GB DDR400/DDR333/DDR266 ECC/ non-ECC un-buffered DDR SDRAM memory
- Dual Channel Memory Architecture


Any help appriciated!!

[teachmech]

Your mother board expects ram to be added in pairs so that it works in daul channel if you can return the 1Gb stick and buy 2 x 512 or better still 2 x 1Gb for 2 Gb as this well alow you to still have 1T command rather than 2T command.

[Psycho Pigeon]

So there's no way I can turn off dual channel or anything like that?