I was running a simple wp site with a hand full of plugins. But my site often gets 404 because dreamhost says my applications were using too much RAM. I asked them what's the cap and never got an answer.
I checked my RAM usage and is only few hundred MBs. With < 100 users per day.
At the end, I switch to a VSP somewhere near Norway and now is running fine.
dreamhost is good only if u're running simple site with no scripts and no users.