I have recently installed a new router (if it's relevant) and whenever I open iCal now I get this message.
I can't remember ever using a password for this and don't know what to do. I have tried all my known passwords but no luck. I can cancel it and proceed ok but confused now. I assume it means I can sync with other dates etc on the web. Any suggestions please?

I can't remember ever using a password for this and don't know what to do. I have tried all my known passwords but no luck. I can cancel it and proceed ok but confused now. I assume it means I can sync with other dates etc on the web. Any suggestions please?