Hardware Error: miscompare on CPU

[noid0]

Hello.
Please explain this issue:

When I run stressapptest with options:

stressapptest -l google_app_test.result -A -W -C 4 --cc_test -s 10000 -
m 2 -i 2

I get such errors:

Report Error: miscompare : DIMM Unknown : 1 : 5277s
Hardware Error: miscompare on CPU 0(0xF) at 0xb74aa0c0(0x0:DIMM
Unknown): read:0x5555555555d75555, reread:0x5555555555d75555 expected:
0x5555555555555555
Report Error: miscompare : DIMM Unknown : 1 : 5277s
Hardware Error: miscompare on CPU 0(0xF) at 0xb74aa0e0(0x0:DIMM
Unknown): read:0x55555555557d5555, reread:0x55555555557d5555 expected:
0x5555555555555555

Status: FAIL - test discovered HW problems


Kernel messages:

kernel:[783819.634701] EDAC MC0: UE page 0x479be, offset 0x4c0, grain
4096, row 1, labels ":": e752x UE from Scruber


What is it memory or CPU error?


Hardware:
Intel Xeon 3.20GHz Socket 604
Supermicro X6DHR-8G
2x1GB DDR 333MHz ECC SDRAM

OS: Debian
Repository linux kernel 2.6.26-2-686

Thanks.