Not Connecting to Internet Upon Wake?

I updated my Macbook Pro yesterday (iPhoto and Macbook Pro Hardware thing), and ever since I did, whenever I wake my Mac from sleep and open up Safari (or Chrome) it is not connected to the internet. It has already established the connection to my Wi-Fi network, yet after refreshing again and again it's still not connected to the internet. The only way I can get it to connect and is by launching System Preferences and turning Wi-Fi off and then on again. It's a serious pain and it would be very helpful if anyone knows a solution. Thanks!