Hey guys,thought i would mention this.I believe the culprit is indeed ZA.I also use ZA security suite mainly for the firewall and every so often i get exactly the same problem.Usually this happens maybe every few days turning ZA off completely eliminates the issue otherwise restarting the PC seems to eliminate the issue for a further few days.Not sure exactly what causes the issue though but i have checked and rechecked and whatever the issue is ZA seems to be the cause.