NTLDR is missing ... error

I had a system with 3 HDDs and a DVD-RW that were all working fine. I
bought a barebones and moved all over to the new box and re-formatted
and reloaded the OS. Now when I have all 3 of the HDDs plugged in, I
get an error:

NDLDR is missing
Press CTRL + ALT + DEL to restart

If I only have 2 plugged in, all works fine. I have the DVD and the
120Gb HDD installed in the primary and the 40Gb and 80Gb installed in
the secondary ports. In all instances, the devices that are plugged
in the primary port are left plugged in. If I have either the 40Gb or
the 80Gby plugged in, it boots up fine. Once I plug both of the
drives in the secondary port, that's when I get the error.

Please help.
Thanks.
Robert

 

I presume N*T*LDR, meaning NT LoaDeR.

Which is the system HDD? It seems to be the 120 Gb, but nothing is sure...
In that case, it isn't a good choice to install it in the same port as the
DVD, since it'll works at its speed. Which are the speeds of each drive
(ATA4, 5, 6... or UDMA33, 66, 100...)?

Here's what I would do:
Install the OS on the 40Gb (or the fastest of the 40Gb and 80Gb). Use the
120Gb as main data drive.
Primary0: system 40Gb HDD, Primary1: data 120Gb HDD
Secondary0: DVD-RW, Secondary1: 80 Gb HDD
Virtual memory shared by the 40Gb and the 120Gb, on dedicated Fat32
clustersize 4K partitions.