This is either a DNS issue or an internet routing issue, upstream from you. My guess is that you can not get to keyclone's website either.

If you open up a command window (Run -> cmd) you can try
nslookup
yahoo.com
google.com
dual-boxing.com

Try a couple other things you can get to and a couple you can't. If they all return IP addresses your DNS is good, if they don't that is the issue.

If DNS is good, try
tracert dual-boxing.com
tracert google.com

Again, try a couple good things and a couple of bad things. Most will stop somewhere before their final destination. If the bad things all seem to stop at the same place, that would indicate where the issue is.

You can save all this info and pass it to your ISP if you decide to open a ticket with them. They should be the ones controlling your DNS server and are better equipped to handle upstream routing issues.

Or, depending on your modem/router, it could be going bad too. If it has some kind of management interface you might want to look at that. You rISP might be able to help you with that as well if they provided it or you bought it from them.

Good Luck.