DH reading google apps mail?

Hello, today I noticed that someone else was logged in my Google Apps mail account (associated with a domain hosted on dh).

In the account activity window, beside my browser session there was an IMAP session from the ip, which is assigned to Dreamhost.
(go to http://whois.arin.net if you want to check)

I’ve promptly contacted DH support asking for an explanation (about 5 hours ago) and didn’t receive any feedback yet.

Has such a thing ever happened to anybody else?