We actually ran into this issue Weds night (4/5/06). Our custom DNS records have been set up and working fine for a year. They were down for over 16 hours yesterday.
We're frustrated too. We requested a callback and got an email 5 hours later (the callback had a 3 hour window) saying it was resolved. AND it showed that we used a callback request, which it shouldn't since we didn't actually GET a call.
I'm a web designer. I'm using Dreamhost for approx 15 domains. My business partner is considering decommissioning his server and moving another 60. My dad, who's got another 18 domains, is the one who had the custom mx records. He was coordinating a meeting with 85 people and had no email for an entire day.
Dreamhost's apparent lack of concern over the major issues these outages are causing is making me seriously consider shopping around. These DNS issues have been going on intermittently for 2 months. When sites go down, my clients (one of whom is my father) call me and expect results...NOW. Telling them I don't know what's going on or when it will be fixed because I have to wait for Dreamhost to communicate isn't getting it.
CrimsonDryad Web Design Services
Web Design, Custom Software Development