Recently I just built a new PC with ASUS P8H97 motherboard (using BIOS 1003) and I noticed this error in dmesg output:
<snip>
ACPI: Core revision 20110413
..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
CPU0: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz stepping 07
Performance Events: PEBS fmt1+, SandyBridge events, Intel PMU driver.
... version:                3
... bit width:              48
... generic registers:      8
... value mask:             0000ffffffffffff
... max period:             000000007fffffff
... fixed-purpose events:   3
... event mask:             00000007000000ff
Booting Node   0, Processors  #1
smpboot cpu 1: start_ip = 98000
 #2
smpboot cpu 2: start_ip = 98000
 #3 Ok.
smpboot cpu 3: start_ip = 98000
Brought up 4 CPUs
Total of 4 processors activated (26489.60 BogoMIPS).
NET: Registered protocol family 16
ACPI: bus type pci registered
PCI: MMCONFIG for domain 0000 [bus 00-3f] at [mem 0xe0000000-0xe3ffffff] (base 0xe0000000)
PCI: not using MMCONFIG
PCI: Using configuration type 1 for base access
bio: create slab <bio-0> at 0
ACPI: EC: Look up EC in DSDT
ACPI: Executed 1 blocks of module-level executable AML code
ACPI Error: [RAMB] Namespace lookup failure, AE_NOT_FOUND (20110413/psargs-359)
ACPI Exception: AE_NOT_FOUND, Could not execute arguments for [RAMW] (Region) (20110413/nsinit-349)
ACPI: SSDT 00000000bf5dec18 0038C (v01    AMI      IST 00000001 MSFT 03000001)
ACPI: Dynamic OEM Table Load:
ACPI: SSDT           (null) 0038C (v01    AMI      IST 00000001 MSFT 03000001)
ACPI: SSDT 00000000bf5dfe18 00084 (v01    AMI      CST 00000001 MSFT 03000001)
ACPI: Dynamic OEM Table Load:
ACPI: SSDT           (null) 00084 (v01    AMI      CST 00000001 MSFT 03000001)
ACPI: Interpreter enabled
ACPI: (supports S0 S1 S3 S5)
ACPI: Using IOAPIC for interrupt routing
<snip>

I'm not sure if this is an error in kernel or in BIOS, as so far all seams to work fine, but I decided to file a bug report just in case. Where should I be looking for manifestations of bug and if this is a BIOS bug, what should I report to the tech support?