Chris, when the system is up it will return "album not found" quickly if the album isn't in the database.
When the database is down then the system hangs for a while before defaulting to a "not found" state.

I was importing some albums last night and the data went down at around 6.35pm (UK time).

I exchanged a few comms earlier in the week with M support about this. They are definitely aware. I agree with Ian that we really need some kind of status indicator. Even if this is somewhere on the M support site.

It's not ideal but all I can think to manage this is tag albums to re-edit when database is back up.

Rgds,
Nick