Cannot Start Avast In lubuntu 12.04

Good morning. I am setting up a new system with lubuntu. I do realise that linux isn’t exactly vulnerable itself, but I do think it is irresponsible not to have antivirus software if you ever share anything with anyone who uses another OS.

my version of lubuntu is amd64, but the avast deb is for i386. i am a computer oldie, linux newbie…

Given that, I followed the directions here:

http://howtoubuntu.org/how-to-install-and-update-avast-antivirus-in-ubuntu

I got a successfull install message, and the avast icon is now in my system menu.

When I click on it, though, nothing happens. No error message, nowhirling mouse pointer indicating something is happening, no indication on the task bar that avast is running.

My understanding is that lubuntu is ubuntu + the LXDE desktop.