Unable to run liveupdate in NIS 2009 even though internet connection ok

Hello, recently my NIS 2009 is unable to run liveupdate even though internet connection is ok. Error message was "unable to connect to the Norton LiveUpdate server. Please check your internet connection".

 

After checking with the ISP, there is no restrictions on their end preventing connecting to the Liveupdate server. Anyone else having the same problem? Hoping someone can help me out there. Thank you.