Try uninstalling the Google toolbar & see if that helps - then you'll know if it may be the culprit.
You're not using the Beta version of the toolbar are you? If yes, install the non-beta version (click here), after uninstalling the beta.
If still no joy, send me a message by clicking on the little envelope next to my user name. I'll send you 3 older verions of the toolbar via email, which you can try as a temporary solution. G