Norton Security Stops Responding/Doesn't Download Program Updates

Pretty much as in the title really.

(1) I've noticed from time to time Norton Security just stops responding. The systray icon still has the green tick but right-clicking it doesn't bring up the menu and double-clicking the desktop item does nothing so I have to reboot my laptop to get it working again.

(2) Also I've noticed that although it downloads/applies the virus definition updates itself it doesn't do so with Norton Security program updates and so I have to periodically run Live Update myself to try and get those.

Would appreciate any advice.