Ammusing sideline on language, reminds me of the 70's when I spent a couple of years in Canada and regularly visited the States. The same word had compleetly diferent meanings. Broadminded, Chips, Gearbox etc,etc.
Anyway, I have tried the optimi(z)sing and though it seems a little better,but it's still there.
My board is an Asus P5E-VM HDMI, 3gig 2core pent' chip, 3gig mem.  It does not have a printer port so on a pci card.

I will try to give a full description of the setup and issues.

Drive 1
IMS IB106.   24v - 80v,  1 - 6 amps,  Full or 1/2 step.
I have 3 of these and they are new.

Drive 2
Superior electric, Slo-Syn, SS2000MD7,  24v - 75v,  1 -7amps,  2 - 100 resolution.
Supposed to be new but I have doubts.

Motor 1
Astrosyn,  L281,  3v, 1.7 amp, 15Kg cm,  Hybrid
I have 2 of these new

Motor 2
Pacific Scientific, Powermax, P22RXA LDS NS 02,  2.7v,  4.6amp, unipolar.
I have 2 of these used.

Motor 3
SuperiorElectric, Slo-Syn, M112 FJ 319B (same as8018 I think) 2.1v, 9.2amp,  840 oz in
Just the one, used

Again I have tried all combinations, with the same results. A lot better than original as I sorted out the diferent logic pin needs of the diferent Drives.
They all produce exacltly the same results.

As I said befor, the drive test say's excelent in all frequencies.

The behavior of the motors is not bad but there is a definate missing beat, slight jump that you can see and hear, must mean they would loose a step or more.  The timing of the glitch is not constant but approx' every second or so.
I have tried diferent velosities and excel' b cant go too fast with no load as they give up.

Cheers John