Help! I Can't open Macrumors using my DSL connection!

I just got a DSl connection in my office through SBC Yahoo and I can't pull up Macrumors and a few other sites on either my Mac or my pc. I've spoken to SBC and they went through the whole routine with me, checking dns #s and all that stuff. I also spoke to the router manufacturer and they say that there is nothing in the router that is blocking the site (we did the whole tenet thing to check it). My next step is to contact SBC again on Monday, but I was hoping one of you techie people may be able to give me some ideas. SBC DSL was not my choice but those over me. I would have gone a different route. Please help if you can!