norton internets security 2011 and windows 7 - smart firewall

I recently upgraded one of my computers to Windows 7 and installed Norton Internet Security 2011.  I am now having some problems with my most frequently visited websites - search, webmail, etc. - the pages won't load or it takes repeated tries for the page to load.

 

I solved this problem on my other computer (XP, Internet Security 2009) by turning off the NIS smart firewall and using windows firewall.  I'd like to do this with my Win 7 / NIS 2011 machine but I'm not sure it can be done if NIS 2011 is installed.  Does anyone know if I can turn on Windows Firewall after disabling Smart Firewall?

 

Thanks!

 

joc512