Stepper Motor and Cable Shielding. Any tips?

In case you follow more groups than just this, I have also posted
this in the Master5 group, with few replies thus far.

I have a semi-sick stepper system, with Dan Mauch's 5 amp boards and
Master5 as the software so far. (I'd like to stay with that one). The
motors are new, 521 oz-inch also from Camtronics.

I lost lots of steps on a bench test, whether I add resistance to the
motor shafts or not (by hand). So I am losing steps somewhere, no
matter how I adjust the feedrates or pulses per inch etc.

I'm starting to suspect RFI or EMI is important and hurting my
system, even if there are other causes on top of that.

Can someone point out any shielding tips with respect to:

1. The parallel port cable (I have already bought some shielded-
twisted paired wires, so I'll be making a cable, but what about
grounding? Ground at one end only, and to the computer casing????)

2. The motors. Do they give off a hailstorm of RFI from the wires?

3. The wires from the breakout board to driver boards. Shield these??

4. Ground my case which holds the 3 drivers? Grounded also to the PC
casing??

5. Anything I may have missed or gotten totally wrong, feel free to
add in. I have, by the way, done a search on shielding in this and
other groups, and gotten a good beginning picture. But I don't feel
that I have the full picture yet. OK, I'm slow !

Thanks for any feedback. Tom.