webshield throttles all internetconnections

when webshield is activated all network slows down nearly to a halt.
using avast free 8.0.1489 on windows 7 ultimate 64 bit
this problem shows only on the 64 bit version , the 32 bit version seems unaffected so i assume there is a program error
tested on http://speedtest.net
webshield off

http://www.ruudoleo.com/uploads/june2013/speedtestnoantivirus.png

webshield on

http://www.ruudoleo.com/uploads/june2013/testinternet.png