MOVB-16 Vista SP1: first bug

Yet another kernel bug triggered by FireFox.

0: kd> !analyze -v
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************

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: c0075000, memory referenced
Arg2: 00000000, 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: 81eabf99, address which referenced memory

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

READ_ADDRESS: GetPointerFromAddress: unable to read from 81f53868
Unable to read MiSystemVaType memory at 81f33420
c0075000

CURRENT_IRQL: 0

FAULTING_IP:
nt!MiAgeWorkingSet+1a2
81eabf99 8b1e mov ebx,dword ptr [esi]

CUSTOMER_CRASH_COUNT: 1

DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT

BUGCHECK_STR: 0xA

PROCESS_NAME: firefox.exe

TRAP_FRAME: 86f8fa54 -- (.trap 0xffffffff86f8fa54)
ErrCode = 00000000
eax=c0802d18 ebx=00a3a000 ecx=00002408 edx=00a39000 esi=c0075000 edi=c080bd38
eip=81eabf99 esp=86f8fac8 ebp=86f8fc44 iopl=0 nv up ei ng nz na pe cy
cs=0008 ss=0010 ds=0023 es=0023 fs=0030 gs=0000 efl=00010287
nt!MiAgeWorkingSet+0x1a2:
81eabf99 8b1e mov ebx,dword ptr [esi] ds:0023:c0075000=????????
Resetting default scope

LAST_CONTROL_TRANSFER: from 81eabf99 to 81e76d84

STACK_TEXT:
86f8fa54 81eabf99 badb0d00 00a39000 81f099a9 nt!KiTrap0E+0x2ac
86f8fc44 81eab9af 8521bf60 00000003 86f8fc80 nt!MiAgeWorkingSet+0x1a2
86f8fc98 81eab3e4 00000002 86f8fcb4 00000001 nt!MiProcessWorkingSets+0x1ff
86f8fcd8 81e57612 00000000 8356e020 00000000 nt!MmWorkingSetManager+0x199
86f8fd7c 81ff1a1c 00000000 aea14805 00000000 nt!KeBalanceSetManager+0x12a
86f8fdc0 81e4aa3e 81e574e8 00000000 00000000 nt!PspSystemThreadStartup+0x9d
00000000 00000000 00000000 00000000 00000000 nt!KiThreadStartup+0x16

STACK_COMMAND: kb

FOLLOWUP_IP:
nt!MiAgeWorkingSet+1a2
81eabf99 8b1e mov ebx,dword ptr [esi]

SYMBOL_STACK_INDEX: 1

SYMBOL_NAME: nt!MiAgeWorkingSet+1a2

FOLLOWUP_NAME: MachineOwner

MODULE_NAME: nt

DEBUG_FLR_IMAGE_TIMESTAMP: 47918b12

IMAGE_NAME: memory_corruption

FAILURE_BUCKET_ID: 0xA_nt!MiAgeWorkingSet+1a2

BUCKET_ID: 0xA_nt!MiAgeWorkingSet+1a2

Followup: MachineOwner
---------