Frank --
If you see this and can add more:
From my experience, when recording long files (more than an hour or so?), the level meters stop working. The peaks keep working and keep changing with the changing signal level, but the actual levels for the signal disappear. This continues even after you stop recording one file and start a new one. Only way to get the meters to reappear is to shut the unit down and power back up again. This is just the level meters -- it keeps recording perfectly, you just can't see level meters.
Also, from my experience, you can record at 16/44.1 -- I've done it numerous times. But the spdif is not reliable, probably 1 times out of 3 when I try to record off spdif (16/44 or 16/48), the unit locks up and must be re-booted. And on the lock-up, I've never had it lock up at any time other than when trying to start a spdif recording. Once the spdif recording starts successfully, it records without a glitch for hours (though the level meters disappear).