1) Possibly, more likly to be DNS than a slow apache.
2) You need to narrow down the problem, does www.yourdomain.com
resolve to an ip address? is it the correct ip address?
does apache serve a page in response to requests for that domain?
3) Internet explorer has "show friendly http error messages" turned
on by default.
4) You need to narrow down the problem. Run a sniffer. Are you
getting a reply to dns querys? Is the browser opening a
connection to port 80 on the web server?
5)Spend a few minutes with google and do your own research.
You can get an address like linuxleo.dynsdns.org for free.
To get dns service for linuxleo.com you will probably have to pay.