As yo may have read in other discussions, Dreamhost support is trying to catch up with its fast growth and they are falling behind. They are in the process of hiring, so I expect this will get better in the future.
You're right, all the plans allow for QT streaming. When support gets back to you, I imagine they'll take care of this.
One thought - has your plan that you signed up for 2 days ago been approved? If approval is still pending, the full features available to paying customers might not be available to you.