Pixelbox

Yesterday I had a problem with Gmail where I couldn't get to my in box. I though this would pass but it didn't and other people in the office were getting on fine. I started by clearing my cache and flushing my DNS but it still didn't work on Safari, Firefox, Flock or Omniweb, even adium and Google notifier didn't work... When I got home I still had the same problem, even after re booting and clearing stuff out again. This morning I tried google's help page and it told me I should log out, then clear my cache and then try again. Which I am happy to say worked! The question is, what caused this??? and why would it effect all my applications? I see others are having the same gmail problems