setting proxy for chrome drives me crazy help

Hi ,
I’ve downloaded google chrome it was working great until I change my network setting and set a proxy for my network and now chrome stop working eventhough I change its proxy from underhood setting which is show me the KDE proxy I tried several times to make it as a no_proxy or direct connect to internet but when I test proxy environment from the shell such as $HTTP_PROXY it shows me the old proxy setting.
how can I get rid of this problem?