I finally understood this stupid DH problem....
of course the techsupport has been so useless on this issue I had to freakin' figure it out myself. techsupport only tells you vague foo about DNS takings two days to refresh and they just regenerate the httpd.conf thinking it would solve everything magically. that's what happen when you put kids on the support.
the thing is support did not even know how to check the important details that makes things fails/works. I know they don't know, because know I know what was wrong with my setup, and if they knew just a little bit about their servers, that would have check that ages before.
I got the tip to solve the problem on this thread actually.
its all beautifully hidden in this sentence.
that's it.... there is multiple instance of mysql and apache running on a same server answering to different IPs. when you create your vhost. the system automatically assign your vhost to an apache instance and a mysql instance.
I'll bet you most people having problem are those like me managing their DNS zones on their own. thing is. dreamhost is doing everything automatically on their DNS but of course not on ours. but support people don't know how to check things apparently. anyway.
to fix this problem
-> in the panel
-> click domains
-> click manage domains
-> spot the line about your broken vhost
-> hit the DNS link
-> check the IP for www* and make sure your entry in your DNS fits.
-> same for mysql (can and most likely IS a different IP.)
it worked on the first shot for me.
I consider dreamhost owe me 6 months of service for this. I never been able to use my account because of this bug they never been able to fix.