It seems like when I'm using Linux it takes a lot longer to resolve hostnames than with using Windows. Also, my brother created a new subdomain for me on his domain and it took a few minutes for the new subdomain to propagate across the domain servers, but about an hour or so later he was able to access it, meanwhile I still can't even after several hours (and we *should* have the same DNS server since we're sharing the internet connection). I just connected to my uni's CS server and I'm able to connect from there too. What's going on? Edit: My brother is using Windows XP, btw.

You are, more than likely, NOT using the same DNS server.