Can't Access MySpace and other sites

Hi, I'm new to these forums and couldn't find the proper place to post this, but hopefully this is ok. I have a dual 1.25GH G4 and an having internet issues with it. It won't let me view sites like MySpace.com, and basically about 50% of the sites I search for on Google. The biggest issue is not being able to view MySpace, but also when I'm just surfing the web or looking for something on Google, I'm usually limited to my results. Sadly, I have to revert back to my windows computer to view myspace and usually to do research since I'm not limited. The connection goes through a DSL modem into a wireless router, then to a wireless access point into a wired router in my room, thus connecting to my computers. All of my windows machines work fine, but my mac is unable to access those sites. The weird thing is, I was fixing a mac for one of my friends and had got done installing a new hard drive and a fresh install of tiger, and I just tried to open MySpace for fun, and it worked. I compared all the settings with the network to my mac and they were all the same, besides the ip address obviously, but I'm totally stumped on why I can't access these sites. Another person I know who has a Macbook has the same issues, both at my house and other places with wireless connections.

The main browser I use is Camino, but Safari does the same thing. Camino tells me:

“Failed to Connect

The connection was refused when attempting to contact www.myspace.com.

Though the site seems valid, the browser was unable to establish a connection.
* Could the site be temporarily unavailable? Try again later.
* Are you unable to browse other sites? Check the computer's network connection.
* Is your computer or network protected by a firewall or proxy? Incorrect settings can interfere with Web browsing.”

Any help would be greatly appreciated!