This has caused problems for some folks because their ISP's DNS cache still has the old address. Here's a post
that talks about a temporary solution until such time as your ISP's cache expires and is refreshed with new information.
The RPTools.net site was moved to new hardware recently by HostGator, our hosting provider. When they moved it the IP address changed. But the DNS records (that convert hostnames to IP addresses) are often cached for some time, anywhere from 24 hours up to a couple weeks.
The proper way to change the IP address of a public-facing site is to shrink the cache times prior to the move, change the IP address, then increase the cache times again.
For example, two weeks before the move the DNS time-to-live values should be dropped to one week. Then 7-8 days in advance, the TTL should drop to 2 days. Then 3-4 days in advance the TTL should drop to 24 hours. And then 36 hours in advance, they drop to 8 hours. Now when the IP address changes, all of the DNS records around the world will catch up within 8 hours. After the change happens, the DNS records are updated and the TTL is reset back to two weeks (or whatever it was originally). It seems HG didn't do this, but I don't have older DNS records so I can't know that for sure.
Sorry for the hassle. And if you make the change mentioned in that other post, please subscribe to that thread or this one and I'll post again when it appears that all caches are cleared and that will serve as your reminder to take out your temporary changes.