Macbook kernel panic, esp. during DLs, kernel_task causing page fault

I've owned a 2010 13" Macbook for a little over a year and throughout that time have often downloaded files from sites like MediaFire and RapidShare without any problems. However in the past few months, initiating downloads from these sites has triggered a seemingly increasing number of kernel panics.

The last report is posted below. As you can see it blames kernel_task for a page fault which I understand is a somewhat notorious issue - kernel_task eating up virtual memory leading to page faults and panics - so I have a general idea of what is going on.

Unfortunately I am not really sure how to handle this on my own. Does anyone have any advice?

Interval Since Last Panic Report:  83011 sec
Panics Since Last Report:          3
Anonymous UUID:                    FCB28F02-082F-426F-8781-83A11FBE511A

Tue Apr 19 05:42:40 2011
panic(cpu 0 caller 0x2aab59): Kernel trap at 0x0604e3c0, type 14=page fault, registers:
CR0: 0x8001003b, CR2: 0x6006d170, CR3: 0x00100000, CR4: 0x00000668
EAX: 0x00030100, EBX: 0x055e9ba0, ECX: 0x055c5a08, EDX: 0x0604e3c0
CR2: 0x6006d170, EBP: 0x2bc03718, ESI: 0x06ef3054, EDI: 0x00000005
EFL: 0x00010206, EIP: 0x0604e3c0, CS:  0x00000008, DS:  0x00000010
Error code: 0x00000000

Backtrace (CPU 0), Frame : Return Address (4 potential args on stack)
0x2bc034f8 : 0x21b510 (0x5d9514 0x2bc0352c 0x223978 0x0) 
0x2bc03548 : 0x2aab59 (0x59aeec 0x604e3c0 0xe 0x59b0b6) 
0x2bc03628 : 0x2a09b8 (0x2bc03640 0x3146f00 0x2bc03718 0x604e3c0) 
0x2bc03638 : 0x604e3c0 (0xe 0x48 0x2bc00010 0x10) 
0x2bc03718 : 0x188be27 (0x55e9ba0 0x55e9ba0 0x1 0x10) 
0x2bc037c8 : 0x188c8f6 (0x2bc039a4 0x1 0x6 0x2bc03890) 
0x2bc039c8 : 0x188cb7a (0x2d8e8800 0x3ea 0x1 0x600eae4) 
0x2bc039e8 : 0x4cc943 (0x611f2c0 0x9420860 0x0 0x2bc03aa4) 
0x2bc03a48 : 0x4b8f68 (0x9420860 0x0 0x2bc03aa4 0x0) 
0x2bc03a98 : 0x357a0a (0x94208a4 0x2d8e8800 0x1 0x1801a8c0) 
0x2bc03c68 : 0x34edd0 (0x2d8e8800 0x14 0x14 0x6) 
0x2bc03ca8 : 0x35046f (0x2d8e8800 0x14 0x6 0x0) 
0x2bc03dd8 : 0x350596 (0x2d8e8800 0x0 0x2bbe6060 0x847e40) 
0x2bc03df8 : 0x336af3 (0x2 0x2d8e8800 0x2bc03e78 0x22729d) 
0x2bc03e38 : 0x323170 (0x2 0x2d8e8800 0x1 0x24a46274) 
0x2bc03ec8 : 0x31f257 (0x5adb004 0x2 0x2d8e8800 0x5029cd) 
0x2bc03ef8 : 0x3203f5 (0x874fc4 0x60e6548 0x2 0x2bc03f74) 
0x2bc03f68 : 0x320663 (0x0 0x2d8e8800 0x0 0x5a0892c) 
0x2bc03fc8 : 0x2a06dc (0x5a08904 0x0 0x2a06eb 0x54dcb7c) 
      Kernel Extensions in backtrace (with dependencies):
         com.symantec.kext.ips(3.2f8)@0x1884000->0x18fafff
            dependency: com.symantec.kext.internetSecurity(1.3f32)@0x1879000

BSD process name corresponding to current thread: kernel_task

Mac OS version:
10J869

Kernel version:
Darwin Kernel Version 10.7.0: Sat Jan 29 15:17:16 PST 2011; root:xnu-1504.9.37~1/RELEASE_I386
System model name: MacBook6,1 (Mac-F22C8AC8)

System uptime in nanoseconds: 1236181700563
unloaded kexts:
com.apple.driver.AppleFileSystemDriver  2.0 (addr 0xfda000, size 0x12288) - last unloaded 176209234005
loaded kexts:
com.symantec.kext.SymAPComm 11.1f102 - last loaded 37610568655
com.sophos.kext.sav 7.2.0
com.symantec.kext.ips   3.2f8
com.symantec.kext.internetSecurity  1.3f32
at.obdev.nke.LittleSnitch   2.2.05
com.apple.driver.AppleHWSensor  1.9.3d0
com.apple.filesystems.autofs    2.1.0
com.apple.driver.AGPM   100.12.19
com.apple.driver.AppleMikeyHIDDriver    1.2.0
com.apple.driver.AppleUpstreamUserClient    3.5.4
com.apple.driver.AppleMCCSControl   1.0.17
com.apple.driver.AppleHDA   1.9.9f12
com.apple.driver.AppleMikeyDriver   1.9.9f12
com.apple.driver.AudioAUUC  1.54
com.apple.driver.AppleLPC   1.4.12
com.apple.driver.SMCMotionSensor    3.0.0d4
com.apple.Dont_Steal_Mac_OS_X   7.0.0
com.apple.iokit.CHUDUtils   364
com.apple.iokit.CHUDProf    366
com.apple.driver.AudioIPCDriver 1.1.6
com.apple.driver.AppleIntelPenrynProfile    17.1
com.apple.driver.ACPI_SMC_PlatformPlugin    4.5.0d5
com.apple.driver.AppleBacklight 170.0.34
com.apple.GeForce   6.2.6
com.apple.driver.AppleUSBTCButtons  200.3.2
com.apple.driver.AppleUSBTCKeyboard 200.3.2
com.apple.iokit.SCSITaskUserClient  2.6.5
com.apple.iokit.IOAHCIBlockStorage  1.6.3
com.apple.driver.AirPortBrcm43224   427.36.9
com.apple.driver.AppleSmartBatteryManager   160.0.0
com.apple.BootCache 31
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0d1
com.apple.driver.AppleAHCIPort  2.1.5
com.apple.nvenet    2.0.15
com.apple.driver.AppleUSBHub    4.1.7
com.apple.driver.AppleUSBEHCI   4.1.8
com.apple.driver.AppleUSBOHCI   4.1.5
com.apple.driver.AppleEFINVRAM  1.4.0
com.apple.driver.AppleRTC   1.3.1
com.apple.driver.AppleHPET  1.5
com.apple.driver.AppleACPIButtons   1.3.5
com.apple.driver.AppleSMBIOS    1.6
com.apple.driver.AppleACPIEC    1.3.5
com.apple.driver.AppleAPIC  1.4
com.apple.driver.AppleIntelCPUPowerManagementClient 105.13.0
com.apple.security.sandbox  1
com.apple.security.quarantine   0
com.apple.nke.applicationfirewall   2.1.11
com.apple.driver.AppleIntelCPUPowerManagement   105.13.0
com.apple.driver.DspFuncLib 1.9.9f12
com.apple.driver.AppleProfileReadCounterAction  17
com.apple.driver.AppleProfileTimestampAction    10
com.apple.driver.AppleProfileThreadInfoAction   14
com.apple.driver.AppleProfileRegisterStateAction    10
com.apple.driver.AppleProfileKEventAction   10
com.apple.driver.AppleProfileCallstackAction    20
com.apple.driver.AppleSMBusController   1.0.8d0
com.apple.nvidia.nv50hal    6.2.6
com.apple.iokit.IOSurface   74.2
com.apple.iokit.IOBluetoothSerialManager    2.4.0f1
com.apple.iokit.IOSerialFamily  10.0.3
com.apple.iokit.CHUDKernLib 365
com.apple.iokit.IOAudioFamily   1.8.0fc1
com.apple.kext.OSvKernDSPLib    1.3
com.apple.driver.AppleHDAController 1.9.9f12
com.apple.iokit.IOHDAFamily 1.9.9f12
com.apple.driver.AppleSMBusPCI  1.0.8d0
com.apple.iokit.AppleProfileFamily  41.4
com.apple.driver.AppleSMC   3.1.0d3
com.apple.driver.IOPlatformPluginFamily 4.5.0d5
com.apple.NVDAResman    6.2.6
com.apple.iokit.IONDRVSupport   2.2
com.apple.iokit.IOGraphicsFamily    2.2
com.apple.driver.BroadcomUSBBluetoothHCIController  2.4.0f1
com.apple.driver.AppleUSBBluetoothHCIController 2.4.0f1
com.apple.iokit.IOBluetoothFamily   2.4.0f1
com.apple.driver.AppleUSBMultitouch 206.6
com.apple.iokit.IOUSBHIDDriver  4.1.5
com.apple.iokit.IOSCSIMultimediaCommandsDevice  2.6.5
com.apple.iokit.IOBDStorageFamily   1.6
com.apple.iokit.IODVDStorageFamily  1.6
com.apple.iokit.IOCDStorageFamily   1.6
com.apple.driver.AppleUSBMergeNub   4.1.8
com.apple.driver.AppleUSBComposite  3.9.0
com.apple.iokit.IOAHCISerialATAPI   1.2.5
com.apple.iokit.IOSCSIArchitectureModelFamily   2.6.5
com.apple.driver.XsanFilter 402.1
com.apple.iokit.IO80211Family   314.1.1
com.apple.iokit.IOAHCIFamily    2.0.4
com.apple.iokit.IONetworkingFamily  1.10
com.apple.iokit.IOUSBUserClient 4.1.5
com.apple.iokit.IOUSBFamily 4.1.8
com.apple.driver.NVSMU  2.2.7
com.apple.driver.AppleEFIRuntime    1.4.0
com.apple.iokit.IOHIDFamily 1.6.5
com.apple.iokit.IOSMBusFamily   1.1
com.apple.kext.AppleMatch   1.0.0d1
com.apple.security.TMSafetyNet  6
com.apple.driver.DiskImages 289
com.apple.iokit.IOStorageFamily 1.6.2
com.apple.driver.AppleACPIPlatform  1.3.5
com.apple.iokit.IOPCIFamily 2.6
com.apple.iokit.IOACPIFamily    1.3.0

I would guess that it is related to Symantec since it looks like that is the kernel extension that crashed. I would try uninstalling and reinstalling Symantec.