Please focus on one computer at a time and one problem at a time. The symptoms indicate a marginal power supply or memory. So, please provide that info.
>Where's that extra 6000 KB from?
It comes from the common practice of measuring memory with the nearest power of 2 (1, 2, 4, 8, 16, etc), which is not the exact number of bytes; e.g., 1 KByte is actually 1,024 Bytes (2 to the 10th power). Larry