ie7 slow opening sites or non opening sites

Well, I have the odd site that won't open, just get the background, or some you could wait for the cows to come home for them to open. My work around was to just use firefox which had no problems with said sites. Just on a lark 'cause I got fed up with seeing IE7 display "detecting proxy setting" everytime I started it up, I went into tools/internet settings/connections and in the Lan part unchecked "auto detect"... lo and behold, the balky sites now work just fine and IE7 fires up right away.