HD-FOX: "USB Drive Not Recognised"

Black Hole

May contain traces of nut
I turned on my HD-FOX for the usual bed-time streaming last night, and was greeted with an on-screen message box something to the effect "USB drive not recognised. You cannot record and your recordings may be damaged." (I will edit in the actual wording next time I see the message).

I have a 2GB UPD permanently plugged in, formatted Ext2 and hosting the custom software. It has never been enabled for recording anyway. Needless to say my usual custom software services were not running so I had to make do with DLNA streaming instead of direct access (I tried rebooting but it just came up with the message box again).

At the moment I have to attend to other pressing matters rather than fiddle about getting things going again, I have powered down at the wall for the day to see if a cold start improves things tonight, but I suspect the UPD has been corrupted somehow. (I also have a feeling this has happened before, but I can't find any references.)

The curious thing is that the HD-FOX thinks it should have a recordable drive plugged in. I wonder what will happen if I boot up with no drive at all.