Well, a lot of sites are "down" right now due to a scheduled, and announced, major move of a whole cluster. Could that be affecting you?
It's unfortunate that you have had bad uptime experience; mine has actually been very good in spite of some recent hardware issues. I guess as with many other things, YMMV when it comes to "uptime".
I can't help but be a little surprised though that you have a forum "up and running for a few years" and found yourself "hacked" without decent/current backups of your data.
DreamHost has been very up front in their TOS, and their documentation, that any "backups" they do are a "courtesy" and are not GUARANTEED to be available. Even if they represented otherwise, which they don't, common sense should prevail when it comes to backing up data that is stored on someone else's machine.
It sounds to me like that might have indeed been the case; were you expecting something else? You should rely upon your backups. It's great that most of the time the DreamHost backups are there for us, but that is not something you should count on always being the case.
I'd certainly hope they told us that if that is what happened. The truth is always best. Of course, DreamHost tech support folks are kind and compassionate, so it is totally in character for them to apologize for your not having something available that they never promised, and for them to commiserate with you. They could have just as easily said that backups are made by them when and if possible, but that you are responsible for your own data, and have pointed you to the TOS.
Hey, I know it's rough to get "hacked". Did you not keep your forum software updated any better than you kept your data backed up?
I can empathize with your situation, and I'd like to have sympathy for you as well ... but I can't. Running and maintaining a website is not an "auto-pilot" kind of thing; you have to take reasonable steps to protect yourself and your data.
While I don't know what you did, or didn't, do to secure your site, you have told me what you didn't do to protect your data - you didn't keep it backed up properly ( rotated and aged) or you would not have been disappointed at all that DreamHost didn't have a backup that you can use instead of your own (since you can't vouch for the integrity of your own backup).
It's a hard lesson to learn, but maybe your posting here will serve as an object lesson to others.