ZA bocking everything even after being uninstalled is a long standing problem that I don't think has ever been fully fixed. There use to be a tool to clean up after ZA but last time I was at the zone labs site I was unable to find it. A quick way to spot this problem is to ping -t [comp ip] and reboot it, you will see about 10-15 pings get through while booting before the ghost of zone alarm kicks in and starts blocking.