Problems with IE7

I had no problems with the beta version of IE7. When I downloaded the latest version I've been experiencing very slow initial connection speeds. I'll explain. I have a wireless router so when the PC boots up it automatically connects to the internet. I have Yahoo's weather widget running which used to connect within a few seconds to show me how dull and miserable the weather will be this week! Problem is since installing IE7 the widget takes approx 2-3 minutes to connect. I can live with that but when the PC boots and I click on the IE7 icon it can take as long to get onto the internet. If I try and do anything else while I'm connectingto the interent then this can bring things to a virtual standstill. I never had this problem with IE6 and as I mentioned the beta version of IE7 was fine. I've recently done a full system restore hoping that it might work better if the PC is back to the way it was when it was shipped. But this has made no difference. Weird thing is when I use Firefox it takes around 10 seconds for that to get going! Once I'm on the internet with IE7 I have no problems surfing it's just the initial connecting that bugs me! I'd be grateful if anyone has any ideas why this is happening?