Hari~

What is the make/model of computer and the motherboard?

Have you actually had a 128Mb strip working in that machine? I have seen motherboards that will not support modules more than 64MB.

I am not quite clear what you are saying..............you put in the 128 and it is only recognised as 64? If you only see a total of 64Mb, please insert the 128Mb on it's own and see what it says.

I would be inclined to test the 128Mb strip in another machine as well. It may be damaged?

Your memory may be rated PC100/133, but your motherboard may not. It might only be PC100? Now, PC133 might be normally expected to work, but if you have mixed PC100 and 133 you might have problems, particularly if the clock latency is different. At the very least they will only run at 100MHz vanman is quite right there

As Undies has pointed out, mixing memory speeds is not a good idea.