Oh My Gosh! I can't believe that solved it. All this time I had been searching for an answer when the Browser itself was the root of the problem.
I had been restarting my computer or logging out and back in to solve the problem. But at least I know an easy way to work around it. Still strange that this happens. I hope this gets fixed.
I am using Windows 7 64 bit
Office Home and Business 2010
Browser Google Chrome version 17.0.963.79 m
I tested it with Internet Explorer and Firfox but the problem only occurs with google chrome.
Thank You All who have replied :)
I have exactly the same installation:
I am using Windows 7 64 bit
Office Home and Business 2010
Browser Google Chrome version 17.0.963.79
I also have IE8
Yes closing the browsers worked but was not practical as I often use excel while also online. Uninstalling and then reinstalling skype has given me a permanent fix (at least so far) so if you also have skype installed you may want to try that too.