Help! RAM Issue

I have sony vaio ar 720 mode. When i bought laptop it came with 2 RAM sticks, each 1 GB (NANYA brand). I bought PNY RAM stick 2 GB. It was the same as mine - PC2-5300/667. I removed one stick and popped in PNY. Everything went fine, Vista showed i have 3 GB, Bios also showed there are 3 GB. Today i got BSOD. Using WinDBG i got this

*** Memory manager detected 6 instance(s) of page corruption, target is likely to have memory corruption.
IRQL_NOT_LESS_OR_EQUAL (a)
An attempt was made to access a pageable (or completely invalid) address at an
interrupt request level (IRQL) that is too high. This is usually
caused by drivers using improper addresses.
If a kernel debugger is available get the stack backtrace.
Arguments:
Arg1: 38881ce1, memory referenced
Arg2: 00000002, IRQL
Arg3: 00000000, bitfield :
bit 0 : value 0 = read operation, 1 = write operation
bit 3 : value 0 = not an execute operation, 1 = execute operation (only on chips which support this level of status)
Arg4: 81ed86bb, address which referenced memory

Debugging Details:
------------------

READ_ADDRESS: GetPointerFromAddress: unable to read from 81f87868
Unable to read MiSystemVaType memory at 81f67420
38881ce1

CURRENT_IRQL: 2

FAULTING_IP:
nt!MiResolveMappedFileFault+d2
81ed86bb 8b421c mov eax,dword ptr [edx+1Ch]

CUSTOMER_CRASH_COUNT: 1

DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT

BUGCHECK_STR: 0xA

PROCESS_NAME: AdobeUpdater.exe

BAD_PAGES_DETECTED: 6

TRAP_FRAME: a6b73acc -- (.trap 0xffffffffa6b73acc)
ErrCode = 00000000
eax=881cc5c9 ebx=881cc5c9 ecx=00000400 edx=38881cc5 esi=00000000 edi=9a98eb60
eip=81ed86bb esp=a6b73b40 ebp=a6b73bbc iopl=0 nv up ei pl zr na pe nc
cs=0008 ss=0010 ds=0023 es=0023 fs=0030 gs=0000 efl=00010246
nt!MiResolveMappedFileFault+0xd2:
81ed86bb 8b421c mov eax,dword ptr [edx+1Ch] ds:0023:38881ce1=????????
Resetting default scope

LAST_CONTROL_TRANSFER: from 81ed86bb to 81eaad84

STACK_TEXT:
a6b73acc 81ed86bb badb0d00 38881cc5 803da000 nt!KiTrap0E+0x2ac
a6b73bbc 81ed7455 00000000 00566eb7 9a98eb60 nt!MiResolveMappedFileFault+0xd2
a6b73c08 81ed499f 00000000 00566eb7 c0002b30 nt!MiResolveProtoPteFault+0x3f4
a6b73cd0 81ef6fff 00566eb7 9a98eb60 00000000 nt!MiDispatchFault+0x9a6
a6b73d4c 81eaabb4 00000008 00566eb7 00000001 nt!MmAccessFault+0x1fb7
a6b73d4c 00566eb7 00000008 00566eb7 00000001 nt!KiTrap0E+0xdc
WARNING: Frame IP not in any known module. Following frames may be wrong.
0012ff94 00000000 00000000 00000000 00000000 0x566eb7

STACK_COMMAND: kb

SYMBOL_NAME: PAGE_NOT_ZERO_VISTA

FOLLOWUP_NAME: MachineOwner

MODULE_NAME: Unknown_Module

IMAGE_NAME: Unknown_Image

DEBUG_FLR_IMAGE_TIMESTAMP: 0

BUCKET_ID: PAGE_NOT_ZERO_VISTA

Followup: MachineOwner

Then i launched windows memory diagnostic tool. Have to say i launched i after i put new RAM stick, and it showed everything is fine. However this time is shows hardware problem detected. I suppose there are some issues with my RAM. However apart from this single BSOD i don't experience any other problem. Haven't got any new BSODs.
Maybe i have to reinstall windows? Put old RAM stick back? Or what are options i can do?

Would appreciate any help

arturs Notebook Geek

axelm Notebook Enthusiast