AAARGH! I'm still getting this problem. I just don't understand it

Here's what I've found
1. It usually happens early in the morning Pacific Eastern Time (I'm In Australia)
2. It is not consistent.
3. It happens with at least two different internet providers - TPG (which goes through Telstra) and Optus
4. The hosts entry does not work
5. If I ping the new ip address with the -r option it identifies it as
www.arcadecontrols.com6. If I enter the ip address in IE or firefox it comes up 404- not found
All this started happening with the new server. I suspect there's a DNS losing the plot after hours.