I got a BSOD and vsdatant shows as the culprit. Here's the debug memory dump info:

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

DRIVER_IRQL_NOT_LESS_OR_EQUAL (d1)
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 kernel debugger is available get stack backtrace.
Arguments:
Arg1: 00009e35, memory referenced
Arg2: 00000002, IRQL
Arg3: 00000000, value 0 = read operation, 1 = write operation
Arg4: b7dfa3e5, address which referenced memory

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


READ_ADDRESS: 00009e35

CURRENT_IRQL: 2

FAULTING_IP:
vsdatant+203e5
b7dfa3e5 8b4c242c mov ecx,[esp+0x2c]

DEFAULT_BUCKET_ID: DRIVER_FAULT

BUGCHECK_STR: 0xD1

LAST_CONTROL_TRANSFER: from 00000000 to b7dfa3e5

TRAP_FRAME: f78baa00 -- (.trap fffffffff78baa00)
ErrCode = 00000000
eax=86cd13b8 ebx=00006e00 ecx=00000002 edx=00000000 esi=00000000 edi=86cd13b8
eip=b7dfa3e5 esp=f78baa74 ebp=00009e09 iopl=0 nv up ei ng nz na po nc
cs=0008 ss=0010 ds=0023 es=0023 fs=0030 gs=0000 efl=00010286
vsdatant+0x203e5:
b7dfa3e5 8b4c242c mov ecx,[esp+0x2c] ss:0010:f78baaa0=00006e00
Resetting default scope

STACK_TEXT:
00009e09 00000000 00000000 00000000 00000000 vsdatant+0x203e5


FOLLOWUP_IP:
vsdatant+203e5
b7dfa3e5 8b4c242c mov ecx,[esp+0x2c]

SYMBOL_STACK_INDEX: 0

FOLLOWUP_NAME: MachineOwner

SYMBOL_NAME: vsdatant+203e5

MODULE_NAME: vsdatant

IMAGE_NAME: vsdatant.sys

DEBUG_FLR_IMAGE_TIMESTAMP: 46e0766a

STACK_COMMAND: .trap fffffffff78baa00 ; kb

FAILURE_BUCKET_ID: 0xD1_vsdatant+203e5

BUCKET_ID: 0xD1_vsdatant+203e5

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

Operating System:Windows XP Pro
Software Version:7.0
Product Name:ZoneAlarm (Free)