next time you can't reach the website, run
code:
ipconfig /flushdns
nslookup msghelp.net
tracert msghelp.net
in the command prompt for some basic debugging.
if nslookup fails or tracert says something like "unable to resolve..", it's a dns issue - try using the msghelp.net ip directly (
http://64.62.180.102/) or, as wj suggested, switching to OpenDNS