NIS 2009 Desktop Icon has suddely disappeared (twice)

I have now had NIS 2009 installed for 5 days, and already the Norton desktop icon has suddenly disappeard from the system tray twice.  Am i still protected while the icon has disappeard?

Why is this happening?  has anyone else got this problem?

I get a message from Norton "Error 8504,4 ". and it tells me to reboot for a connection.

Once I reboot, all is ok again.