Odd behavior with deepbit's MH/s calculation (normally wrong, now showing 0!)

I've been running two boxes (170mh/s and 360mh/s respectively) on deepbit the last day or so. Two odd things I've been noticing, the last being somewhat alarming:

1. The mh/s on deepbit seems consistently below what my Diablominer is showing me (as per above). Deepbit is normally telling me that I'm getting 400-500mh/s. So it seems like I'm losing data somewhere?

2. Deepbit is now showing me 0 mh/s. The history column is showing a steep decline (from 400-500 mh/s down to 0) as of the last few hours (eg., 500 mh/s, 250 mh/s, 80 mh/s, now zero). I just pinged both my machines are they're running fine. Deepbit has been reporting 0 mh/s for a while now for both of my machines combined.

Has anyone else seen this behavior? Advice / input / suggestions?

Thanks,

N