Firefox not working

Hello all, I dont know y my firefox doesnt work, but my Knoqurer works fine, my firefox is able to resolve the domain name, but waits saying connecting.... and gives a time out message.. this is the same even in my ubuntu live boot cd, can any one give me any clue why this is happening? only knoqurer is working.... even gaim or any other browser dont work.. why ? any clue? -- PEEVEE