Erratic DNS issues
Hello,This is a problem I've been struggling with for a little while, and since I can't seem to be able to figure out any solution to it, I thought I'd ask here. Hopefully someone can help.

I often have trouble accessing my personal website (http://www.moopy.nu/) from my home connection. My ability to access it seems completely random in fact. Sometimes it will work, other times it won't, and I get 'www.moopy.nu cannot be found' errors. Often however, I can indeed access it if I omit the "www", but not otherwise.
From work however, I have absolutely no problems accessing the website whenever I want.
Now the strange thing is, even when I can't access my personal website, I can access all other sites on my server fine, so I don't think this is an issue with my ISP?
The zone files for moopy.nu are seemingly exactly the same as the zone files for all other domains hosted on my server, so I'm not sure why I'm having this problem. Indeed, DNSReport.com seems to give the same output for moopy.nu as it does for all other domains hosted on the server.
What really worries me though is that recently, I've noticed the exact same behaviour happening with a customers' domain as well, so I'd really like to get this issue sorted!
Any help would be very much appreciated!