Sometimes there can be an issue in the path from your ISP to the site you are trying to get to...think of it as driving to different places, and coming to a tree in the road. The tree blocks your access and you can't get through until it's gone.
If you click Start, Run, and type in CMD on your computer, then type in this: tracert www.yahoo.com then hit Enter, you will see the path that you have to travel to get to yahoo. Then type in this: tracert www.rescreatu.com and you will see the path that you have to travel to Rescreatu. That should give you a better idea of how it works, and why sometimes some sites work and others do not. =)
Either way, glad it is working for you now!