Only pop-up I've seen lately has been the 'Smart Scan'. As smart scan basically combines a scan similar to the brief scan one sees when avast! is first installed along with the network scan, really not worth the cpu cycles and time to run. Running network scan alone by itself is a different matter entirely. It takes less time, and leave knowing the network is in good shape. Anyway, running a static file virus scan is generally a waste of time as it is the real-time scanning capabilities of avast! that counts in protection. So the smart scan is never run because of that.
@DavidR,
Sorry to hear about your netbook. Seems many devices are made to be somewhat disposable these days, either thru obsolescence or by design.
I'd recommend a Dell. Dell has come back from the dead since Michael Dell regained control of it. Seems quality and bang for the buck is back over there.