What is the lightning bolt icon in iCal? I've gone through this document, but it's for iCal 3.0, Lion has 5.0+.

http://docs.info.apple.com/article.html?path=iCal/3.0/en/symbls.html

Here's what it looks like, I'm not sure if it's a bolt or a tilde:



Hovering over it gives you no information about it, and it disappears shortly after creating the event...
It means iCal is having difficulty sync-ing with iCloud, or google Calendar. Or some other calendar services that you have.