Strange mem problem

My dad has an Asus A7V133 mobo. He decided to get some extra mem due to the low prices, but it doesn't work

he has 128mb pc 133.
he bought 2x 512mb (64x4) to replace the 128mb.

But the 2 512mb doesnt'work at all.. one works fine alone, the other works fine too, but not together.
They also work fine each in combination with the 128mb simm.

but any given combination of slots used that uses both 512mb simm gets the pc to crash or only to recognize 128mb

The BIOS recocgnizes all simms, though...any ideas anyone?

What's the OS?

Problem occurs both in Win98 AND W2Kpro

Is this registered memory or unregistered?

PixelMover said:

Problem occurs both in Win98 AND W2Kpro

Click to expand...

There will be some problems with W98SE & the fix is located here for 1G & over of ram & here if you have between 512Mb & 1Gb. If the problem is still there with W2K PRO then it's something else. Maybe bad sticks....

it is unregistered mem AFAIK....