Thanks Matttail for the response. Yes, I'd been on SSH last night and this morning. Then things just stopped working after a few connect attempts. I emailed support about it and they responded that my IP had been blacklisted and that they would add it to their whitelist. I've tried several times since just to connect (no login prompt yet) and I'm still getting a connection dropped failure.
If anyone knows of other web hosts that are even remotely comparable to DH (in terms of ssh access, php5, PHP-CGI), I am interested to know.