What is your operating system and service pack and is IE totally up to date including all its add-ons? This applies whether or not you use IE at all as your default browser. (If Vista or Win 7 it should be IE9, XP. IE8)
Go to your Control Panel > Programs > Uninstall a Program (Add or Remove Programs in XP) and uninstall Bing toolbar if you do not want it.
Next run Stinger and Malwarebytes Free to make sure you have no malware installed. They are linked under the last link in my signature below.
Finally open SecurityCenter and click Web and Email Protection, then Firewall
Open the Intrusion Protection drawer and check that item is set to basic and click Apply
See if nthat helps, if not uncheck that item altogether.
That particular item is new and still causing some problems.
I would open a case with Technical Support - it's free and available via phone or online chat through the link under Useful Links at the top of this page.