ethernet flaky with servos?

["Keith R. Bolson" <krbolson-at-visi.com>]

Hello All -
I have a difficult that's not quite on the main topic
of this list.
  When my motors are on and holding position,
my local ethernet segment goes to heck.  Not just the
test machine, but everything attached to the switch.  When
the motors are on, but idling, I see some network errors, but
it is still usable.  I have a linksys 8-port workgroup switch
and UTP cat5 cabling.  The motors have no load - bench
system - and the drives and motors are in a steel shelf.
Would STP cabling or gobs of shielding be useful?
Has anyone had similar experiences?
Thank you.  --krb