Certain websites not loading

I cannot get my Macbook Pro (running 10.5.8) to load certain websites like: Google, Flickr, Vimeo, Yahoo or Youtube.

I've tried OpenDNS to practically no avail (Google worked for a bit), ran Macscan, flushed the DNS cache, cleared stuff with Onyx, ran disk repair, file system check, all that I could see or think of.

What could this be? Any possible solutions?

Thanks

Edit: Forgot to mention, there are 2 other computers (both running Leopard) in the same house and every site works fine on those computers. I also switched service providers today (for unrelated reasons) and the problem persists.

Are you on Dialup? When I still was my MacBook would go to a very limited selection of sites.

No, I've got DSL. I'm plugged straight into the modem but tried airport too which isn't working either.

Hmm. Very odd indeed. Try a different browser.

I have, I've tried Camino, Safari and Firefox. I used open DNS again and managed to get Google to load however Youtube, Vimeo, Yahoo, Flickr and those sites still won't load.

I too am having this problem but not with only those sites its at random. Some days google will load fine others it wont open. There seems to be no rhyme or reason to it either. I have a 6 year old dell desktop that runs every site fine or even faster when this happens. Its so frustrating. Could it be the new safari Beta? By the way I am running on 12mb download 6mb upload DSL. Apple Wireless routers. Even if I am hardwired into the network it will still not open sites.

Have a look at other posts re setting the DNS numbers for your ISP in Network settings of both Airport and Ethernet selections and as well add a Location for the place where u use the Laptop the most. Method varies slightly between Tiger and Leopard.