What is causing this kernel panic?

[lizdemonster]

It happens when I am watching a show on Hulu or another online player. I did a RAM test with the install CD but nothing extraordinary happened.

Below is the error report I got upon restarting:

Interval Since Last Panic Report:  797866 sec
Panics Since Last Report:          2
Anonymous UUID:                    94B36A8B-C3C1-422E-BDC8-9044393F2CB0

Tue Apr 12 14:38:31 2011
panic(cpu 1 caller 0x00194B15): "pmap_flush_tlbs() timeout: " "cpu(s) failing to respond to interrupts, pmap=0x871789c cpus_to_respond=0x1"@/SourceCache/xnu/xnu-1228.15.4/osfmk/i386/pmap.c:4582
Backtrace (CPU 1), Frame : Return Address (4 potential args on stack)
0x343afbe8 : 0x12b4c6 (0x45f91c 0x343afc1c 0x13355c 0x0) 
0x343afc38 : 0x194b15 (0x465c58 0x871789c 0x1 0x195234) 
0x343afca8 : 0x197eb4 (0x871789c 0x18d56000 0x0 0x0) 
0x343afd88 : 0x16087d (0x871789c 0x18d56000 0x0 0x77376) 
0x343afde8 : 0x163170 (0x2fbcad0 0x871789c 0x18d56000 0x0) 
0x343aff58 : 0x1ab39c (0x5100d90 0x18d56000 0x0 0x3) 
0x343affc8 : 0x1a160d (0x8289ee0 0x0 0x10 0x8289ee0) 
No mapping exists for frame pointer
Backtrace terminated-invalid frame pointer 0xbfff80d8

BSD process name corresponding to current thread: Google Chrome He

Mac OS version:
9L31a

Kernel version:
Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386
System model name: MacBook2,1 (Mac-F4208CAA)

System uptime in nanoseconds: 59708924829460
unloaded kexts:
com.apple.driver.CSRHIDTransitionDriver	2.1.9f10 - last unloaded 6111376057207
loaded kexts:
com.paceap.kext.pacesupport.leopard	5.7.2
com.pctools.iantivirus.kfs	1.0.1
com.digidesign.iokit.DigiIO	8.0.3f1
com.digidesign.iokit.DigiDal	8.0.3f1
com.apple.driver.CSRHIDTransitionDriver	2.1.9f10 - last loaded 6039070233441
com.apple.iokit.IOBluetoothSerialManager	2.1.9f10
com.apple.filesystems.autofs	2.0.2
com.apple.driver.AppleHDA	1.7.1a2
com.apple.driver.AppleUpstreamUserClient	2.7.5
com.apple.Dont_Steal_Mac_OS_X	6.0.3
com.apple.driver.AppleHDAController	1.7.1a2
com.apple.driver.AppleIntelGMA950	5.4.8
com.apple.driver.AppleIntelIntegratedFramebuffer	5.4.8
com.apple.driver.SMCMotionSensor	2.1.1d2
com.apple.iokit.IOFireWireIP	1.7.7
com.apple.driver.AppleIRController	113
com.apple.driver.AudioIPCDriver	1.0.6
com.apple.driver.ACPI_SMC_PlatformPlugin	3.4.0a17
com.apple.driver.AppleLPC	1.3.1
com.apple.driver.AppleBacklight	1.6.0
com.apple.driver.AirPort.Atheros	320.16.2
com.apple.driver.CSRUSBBluetoothHCIController	2.1.9f10
com.apple.driver.AppleUSBTrackpad	1.7.4f1
com.apple.driver.AppleUSBTCKeyEventDriver	1.7.4f1
com.apple.driver.AppleUSBTCKeyboard	1.7.4f1
com.apple.driver.AppleUSBMergeNub	3.5.2
com.apple.iokit.IOSCSIMultimediaCommandsDevice	2.1.1
com.apple.iokit.SCSITaskUserClient	2.1.1
com.apple.driver.XsanFilter	2.7.91
com.apple.iokit.IOATAPIProtocolTransport	1.5.3
com.apple.driver.AppleUSBHub	3.4.9
com.apple.iokit.IOUSBUserClient	3.5.2
com.apple.driver.AppleFWOHCI	3.9.7
com.apple.iokit.IOAHCIBlockStorage	1.2.2
com.apple.iokit.AppleYukon2	3.1.13b2
com.apple.driver.AppleAHCIPort	1.7.0
com.apple.driver.AppleIntelPIIXATA	2.0.1
com.apple.driver.AppleUSBEHCI	3.4.6
com.apple.driver.AppleUSBUHCI	3.5.2
com.apple.driver.AppleEFINVRAM	1.2.0
com.apple.driver.AppleSmartBatteryManager	158.10.5
com.apple.driver.AppleRTC	1.2.3
com.apple.driver.AppleHPET	1.4
com.apple.driver.AppleACPIPCI	1.2.5
com.apple.driver.AppleACPIButtons	1.2.5
com.apple.driver.AppleSMBIOS	1.4
com.apple.driver.AppleACPIEC	1.2.5
com.apple.driver.AppleAPIC	1.4
com.apple.security.seatbelt	107.12
com.apple.nke.applicationfirewall	1.8.77
com.apple.security.TMSafetyNet	3
com.apple.driver.AppleIntelCPUPowerManagement	76.2.0
com.apple.driver.DiskImages	199
com.apple.BootCache	30.4
com.apple.iokit.IOSerialFamily	9.4
com.apple.driver.DspFuncLib	1.7.1a2
com.apple.iokit.IOHDAFamily	1.7.1a2
com.apple.iokit.IOAudioFamily	1.6.9fc5
com.apple.kext.OSvKernDSPLib	1.1
com.apple.driver.IOPlatformPluginFamily	3.4.0a17
com.apple.driver.AppleSMC	2.3.1d1
com.apple.iokit.IONDRVSupport	1.7.3
com.apple.iokit.IOGraphicsFamily	1.7.3
com.apple.iokit.IO80211Family	216.1
com.apple.driver.AppleUSBBluetoothHCIController	2.1.9f10
com.apple.iokit.IOBluetoothFamily	2.1.9f10
com.apple.iokit.IOUSBHIDDriver	3.4.6
com.apple.driver.AppleUSBComposite	3.2.0
com.apple.iokit.IOSCSIBlockCommandsDevice	2.1.1
com.apple.iokit.IOBDStorageFamily	1.5
com.apple.iokit.IODVDStorageFamily	1.5
com.apple.iokit.IOCDStorageFamily	1.5
com.apple.iokit.IOSCSIArchitectureModelFamily	2.1.1
com.apple.iokit.IOFireWireFamily	3.4.9
com.apple.iokit.IONetworkingFamily	1.6.1
com.apple.iokit.IOAHCIFamily	1.5.0
com.apple.iokit.IOATAFamily	2.0.1
com.apple.iokit.IOUSBFamily	3.5.2
com.apple.driver.AppleEFIRuntime	1.2.0
com.apple.iokit.IOSMBusFamily	1.1
com.apple.iokit.IOStorageFamily	1.5.6
com.apple.iokit.IOHIDFamily	1.5.5
com.apple.driver.AppleACPIPlatform	1.2.5
com.apple.iokit.IOACPIFamily	1.2.0
com.apple.iokit.IOPCIFamily	2.6