Good news: Dan in support has this in hand. Seems a user's script had been leaving behind a growing number of vestigial processes, causing locking issues. Resources were being consumed in a very atypical way, making the diagnosis tricky. Kudos to the guys who had to stare at server diagnostics for hours on end to finger the cause!
Last, every hosting company has technical problems. It's the nature of the business. And it's really frustrating when it's your box on the fritz. But as I told Dan, I like hosting with DreamHost, and even take it as a point of pride (as in, "look what a great decision I've made"). In this forum, you can read the occasional tirade against some "shattered illusion of perfection", replete with the threats to march out of here, harumphing and stomping loudly to the next host. You can also read the abandoned threads blithely left behind by those whose troubles have been solved. Perhaps they've just forgotten their initial panic, or they're afraid they'll appear too fawning if they bestow a little praise. But when your vendors respond to trouble like these guys do, you have to pay them some sort of gratitude. In a searchable forum, the world knows you've had an issue. They should find out when DH has brought you the cure.
For those of you who find yourself in a pickle, remember that you're dealing with smart people on the other end. Harsh words are unnecessary (and possibly unproductive). Be clear, concise, persistent, and patient; and you'll see these folks resolve nearly any issue.