filmscanners: VueScan: Fails on LinoScan/UMax flatbed?

[MCRich <m.rich@visi.com>]

I get only severely degraded scans on my LinoScan1400 when using VueScan
with any settings permutation.  The root symptom seems to be the raw 16-bit
scan file, which always approaches near-black:  mean ~4, std dev ~2 in
histogram.  Both internal VueScan and external PS processing of the scan
yield image histograms posterized moderately in 16-bit and radically in
subsequent 8-bit mode conversion.  Films being used are 4x5 negs, bw and
color.

In other software/hardware combinations I can produce the smooth-as-butter
losslessly-editable 16-bit files I want.    From 35mm film the
SS4000/VueScan team produces histograms so undulating and and full-bodied I
lust to osculate the monitor.  LinoColor software renders a similarly fine
file with the LinoScan flatbed from 4x5 color negs (though not as yet from
bw negs.)

Inasmuch as my ultimate goal is often greyscale prints from 4x5 negs I¹d
dearly desire VueScan to work with the LinoScan.

Is my experience characteristic of the VueScan/Linoscan[UMax] combination or
somhow idiot-syncratic?
Can anyone suggest a settings combination that works?

Mike Rich