Quietly we read <dhigg4$s9c$1@gnus01.u.washington.edu>, unable to contain our credulity we realized that Max Power <mikehack@u.washington.edu> said this:

Quietest SETI unit recorded? Some of these WUs must exist...

General requirements for a quiescent WU:
1. No Gaussians

You can fit a Gaussian to random noise, it just would be a very poor fit. You would have to specify how poor for this post to make any mathematical sense.

2. No Triplets
3. No 'spikes' of any kind that would show up on the meter

Unless all readings are identical you will also get spikes.

4. No 'Doppler effects in the signals
=> I hope I have covered all the bases...

Having said the above I had a very flat WU that completed in 6 hours when they normally take 12 or more on my computers.  It had a very small result.sah file.  Wish I'd kept a copy.