I have the same issue - started with the two most recent Avast program updates - currently Avast 2014.9.0.2016.
For some reason, if I power-cycle the Network printer, the job will print. But its like Avast is taking the printer "off-line."
I did find that if I disable the Web Shield, the printer works as before.
I'm not sure how to back out of the most recent program update and install an older version, but this sure looks like an Avast issue. I've had the same home network for several years, same PC (Win 7 - 64) and same HP 3390 printer and driver.