Safari Problems when Internet connection drops

Since (I think but cannot be certain) 10.7.4 I've had a really annoying problem on Safari (currently6.0).

If my internet connection drops out, whatever website I'm on at the time becomes unavailable to me when the internet connection is restored. It just hangs as if trying to open with the blue progress bar stalled half way across the site name in the browser strip.

I can't just reset safari, I have to shut down the macbook and start again.

Any ideas?