64-bit 13.10 shows 1GB less RAM than 64-bit 13.04 did

Multiple 64-bit versions (Kubuntu, Lubuntu and Xubuntu) once installed on my ThinkPad R60 show 3GB of RAM, not the correct 4GB of RAM. Last week with 13.04, I had 4GB of RAM (which matches the BIOS) and this week I have 3GB available.

Here's a biopsy report on the wee beastie, and I surely would appreciate help with the problem.

Linux R60 3.11.0-12-generic #19-Ubuntu SMP Wed Oct 9 16:20:46 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux r60

free -m reports

_ total used free shared buffers cached

Mem: 3001 854 2146 0 22 486

-/+ buffers/cache: 346 2655

Swap: 0 0 0

. . . . . .

lshw shows:

description: Notebook

product: 9459AT8 ()

vendor: LENOVO

version: ThinkPad R60/R60i

serial: redacted

width: 64 bits

capabilities: smbios-2.4 dmi-2.4 vsyscall32

configuration: administrator_password=disabled boot=normal chassis=notebook family=ThinkPad R60/R60i frontpanel_password=unknown keyboard_password=disabled power-on_password=disabled uuid=126E4001-48CA-11CB-9D53-B982AE0D1ABB

*-core

description: Motherboard

product: 9459AT8

vendor: LENOVO

physical id: 0

version: Not Available

*-firmware

description: BIOS

vendor: LENOVO

physical id: 0

version: 7CETC1WW (2.11 )

date: 01/09/2007

size: 144KiB

capacity: 1984KiB

capabilities: pci pcmcia pnp upgrade shadowing escd cdboot bootselect socketedrom edd acpi usb biosbootspecification

{snip}

*-memory

description: System Memory

physical id: 29

slot: System board or motherboard

size: 4GiB

*-bank:0

description: SODIMM DDR2 Synchronous

physical id: 0

slot: DIMM 1

size: 2GiB

width: 64 bits

*-bank:1

description: SODIMM DDR2 Synchronous

physical id: 1

slot: DIMM 2

size: 2GiB

width: 64 bits