Safari automatically downloads "Unknown" file

Question

In the last few days I have found that Safari automatically downloads files called "Unknown". It sometimes happens when I am using another application so it doesn't seem related to something that I have just done. Also I find that Safari is DEAD slow with some pages or part of the content of some pages.
Here's what I have tried so far. I have deleted all the plist files in both the user account and the library folder in the system folder. I have zapped the PRAM, rebuilt permissions and restarted in safe mode. I have Resert Safari and Emptied the Cache under the Safari menu. I have also updated my antivirus and run it. Nothing has helped.
The sites that load slowly do not behave the same way in Firefox, but I would like to use Safari for most of these most of the time. Any suggestions of a cure would be most welcome.

Answer 1

Hi Linc.
Thank you very much for the time you are taking. I hope what follows makes more sense to you than it does to me.
Step 1 =
at.obdev.nke.LittleSnitch (2.5.2)
com.Logitech.Control Center.HID
com.attotech.driver.ATTOiSCSI (3.4.1b1)
com.eltima.SyncMate.kext (0.2.5b15)
com.intego.kext.NetBarrierKPI (10.5.2)
com.intego.kext.AppBarrierKPI (2.0)
org.virtualbox.kext.VBoxDrv (2.2.0)
org.virtualbox.kext.VBoxUSB (2.2.0)
org.virtualbox.kext.VBoxNetFlt (2.2.0)
org.virtualbox.kext.VBoxNetAdp (2.2.0)
Step 2 =
com.eltima.async.rapiback
com.paceap.pacesupport
com.intego.task.manager.daemon
com.intego.netbarrier.daemon
com.datarobotics.ddserviced
com.datarobotics.ddservice64d
com.barebones.textwrangler
com.attotech.iscsid
com.adobe.SwitchBoard
at.obdev.littlesnitchd
Step 3 =
com.wacom.wacomtablet
com.adobe.CS5ServiceManager
at.obdev.LittleSnitchUIAgent
at.obdev.LittleSnitchNetworkMonitor
com.zeobit.MacKeeper.Helper
com.tastyapps.SpiceRack
com.akamai.client.plist
com.adobe.AAM.Scheduler-1.0
Step 4 =
/Library/Installer Log File
/Library/Components:
/Library/Extensions:
VBoxDrv.kext
VBoxDrvTiger.kext
VBoxNetAdp.kext
VBoxNetFlt.kext
VBoxUSB.kext
VBoxUSBTiger.kext
/Library/Frameworks:
Adobe AIR.framework
DXFAppKit.framework
DXFCorrection.framework
DXFFoundation.framework
EDWOCommon.framework
EDWOInternet.framework
EWSMac.framework
HPDeviceModel.framework
IntegoiCalFramework.framework
KodakCMS.framework
MacFUSE.framework
NyxAudioAnalysis.framework
PluginManager.framework
StuffIt.framework
StuffItCore.framework
/Library/Input Methods:
/Library/InputManagers:
LCC Scroll Enhancer Loader
SIMBL
/Library/Intego:
.netbarrier_info
IMailSenderTool
IntegoStatusItem.bundle
MIME.plist
integod
netbarrierd.bundle
/Library/Internet Plug-Ins:
.DS_Store
Disabled Plug-Ins
Flash Player.plugin
Flip4Mac WMV Plugin.plugin
Flip4Mac WMV Plugin.webplugin
GarminGpsControl.plugin
JavaAppletPlugin.plugin
NP-PPC-Dir-Shockwave
Quartz Composer.webplugin
QuickTime Plugin.plugin
RealPlayer Plugin
RealPlayer Plugin.xpt
WacomNetscape.plugin
WacomSafari.plugin
flashplayer.xpt
iPhotoPhotocast.plugin
nsIQTScriptablePlugin.xpt
/Library/Keyboard Layouts:
Logitech.bundle
/Library/LaunchAgents:
at.obdev.LittleSnitchNetworkMonitor.plist
at.obdev.LittleSnitchUIAgent.plist
com.adobe.AAM.Updater-1.0.plist
com.adobe.CS5ServiceManager.plist
com.wacom.wacomtablet.plist
/Library/LaunchDaemons:
PACESupport.plist
at.obdev.littlesnitchd.plist
com.adobe.SwitchBoard.plist
com.apple.third_party_32b_kext_logger.plist
com.attotech.iscsid.plist
com.barebones.textwrangler.plist
com.datarobotics.ddservice64d.plist
com.datarobotics.ddserviced.plist
com.intego.netbarrier.daemon.plist
com.intego.task.manager.daemon.plist
rapiback.plist
/Library/PhonePlugins:
Sony-Ericsson-Aino-U10a.phoneplugin
Sony-Ericsson-Aino-U10i.phoneplugin
Sony-Ericsson-J10.phoneplugin
Sony-Ericsson-J108a.phoneplugin
Sony-Ericsson-J108i.phoneplugin
Sony-Ericsson-J10i.phoneplugin
Sony-Ericsson-J20.phoneplugin
Sony-Ericsson-J20a.phoneplugin
Sony-Ericsson-J20i.phoneplugin
Sony-Ericsson-Pureness-X5.phoneplugin
Sony-Ericsson-W20.phoneplugin
Sony-Ericsson-W20a.phoneplugin
Sony-Ericsson-W20i.phoneplugin
Sony-Ericsson-Yari-U100.phoneplugin
Sony-Ericsson-Yari-U100a.phoneplugin
Sony-Ericsson-Yari-U100i.phoneplugin
/Library/PreferencePanes:
Flash Player.prefPane
Flip4Mac WMV.prefPane
GlimmerBlocker.prefPane
Growl.prefPane
Logitech Control Center.prefPane
WacomTablet.prefPane
/Library/PrivilegedHelperTools:
com.barebones.textwrangler
/Library/QuickLook:
GBQLGenerator.qlgenerator
iWork.qlgenerator
/Library/QuickTime:
AppleIntermediateCodec.component
AppleMPEG2Codec.component
DivX Decoder.component
Flip4Mac WMV Advanced.component
Flip4Mac WMV Export.component
Flip4Mac WMV Import.component
/Library/ScriptingAdditions:
Adobe Unit Types.osax
LCC Scroll Enhancer Loader.osax
/Library/Spotlight:
AppleWorks.mdimporter
GBSpotlightImporter.mdimporter
Microsoft Office.mdimporter
iWeb.mdimporter
iWork.mdimporter
/Library/StartupItems:
IntegoCommon
NetBarrierKPI
PACESupport
VirtualBox
/etc/mach_init.d:
dashboardadvisoryd.plist
/etc/mach_init_per_login_session.d:
/etc/mach_init_per_user.d:
com.adobe.SwitchBoard.monitor.plist
Library/Address Book Plug-Ins:
SkypeABDialer.bundle
SkypeABSMS.bundle
Library/Fonts:
Library/Input Methods:
.localized
Library/Internet Plug-Ins:
ClickToFlash.webplugin
Library/Keyboard Layouts:
Library/LaunchAgents:
com.adobe.AAM.Updater-1.0.plist
com.akamai.client.plist
com.tastyapps.SpiceRack.plist
com.zeobit.MacKeeper.Helper.plist
Library/Mail/Bundles:
Library/Mail/Bundles (Disabled 1):
Letterbox.mailbundle
Library/Mail/Bundles (Disabled):
Library/PreferencePanes:
Perian.prefPane
Library/QuickTime:
AC3MovieImport.component
Perian.component
Library/ScriptingAdditions:
SpiceShaker.osax
Library/Services:
BlueHarvest Service.service
Step 5 =
ColorVisionStartup, SMARTReporter, SoundSource, Ejector, Logitech Control Center Daemon