As many of you would have noticed, tonight we were offline for about five hours... and according to the server host, it was planned maintenance on the server that housed our domain and others... but didn't think to warn us first.

That would probably be our worst outage of that server host, which is motivation enough to track down someone new, even if it costs more than this one.
It's bad that it keeps going offline every month or two, but it is worse that everytime it goes offline, it is outside of business hours, which means having no one to chase up about it, other than an answering service on the end of an "emergency" after hours number.