** SOLVED **
Support resolved the issue (quite speedily I might add, Thanks DH support team!), which was a glitch in their update system.
I'm having trouble logging in via ssh as a specific user. I can log in with my main account just fine. I have reset the password (using the web interface) of the other account and waited ~half an hour, but am still unable to log in with that username.
It appears that the $HOME directory for the account I am unable to log in as has been removed entirely from the server (which in my case is lara.dreamhost.com). This account was created several months ago, but has not been used recently, so I'm not sure when the trouble started.
Maybe worth mentioning, that the username in question may appear to someone who does not recognize it's origin as a random series of gibberish characters. So, I'm guessing there is a possibility that a sysop believed the account was illegitimate? It isn't.
Any advice on how to proceed?