Memory full

It isn't an older camera with a 32Mbyte limit is it?

I am very leery of formatting or writing to a card from my computer. The
formatting can be different and the cache in your computer may. not have
written out the data. I got caught transferring some files at work this with
a dongle containing SD memory. I took the dongle back to the shop,
reformatted it and wrote the files again. I then reread the files and even
opened a doc file checking all is fine. After removing the dongle and
replacing the files were gone. Seems I didn't read the error close enough
when I removed it. You know how Windows complains about removing USB items
without telling it first? Well it turns out the cache wasn't written to the
USB dongle at all until I used there little shutdown procedure first.

Got to turn that writeback cache crap off.

No, according to Konica it can handle any size MMC/SD card.
Today the batteries went low and it turned itself off. When I replaced them,
the card appeared to show two files that had disappeared on a previous
occasion, and the movie clips I had just been taking had vanished. When I
deleted those two files, today's movies reappeared.

Is this some quirk of the FAT filing system on these cards, or a bug in the
camera??

Oh yes, I agree. I wouldn't actually use the card in the camera as a storage
device for anything other than what the camera has put on there.

I have concluded that, since the camera manual only refers to SD cards, I
ought to be using an SD card rather than MMC which I understand is a slower,
more error-prone media anyway.

I do try to disconnect the camera after first asking Windows, now you
mention that cache I will always do it!