Wheel shimmy

steering wheel shimmy at 15, 45
mph. Same when turning or going
straight at those speeds and on
uneven pavement (recessed manhole
covers). I've had the following
replaced/repaired--LCA, shocks,
struts, both half shafts, tie rods,
hydraulic motor mount, wheel
bearings. It also has new brakes,
tires, and was road forced
balanced(tires) and aligned. no play
in the wheel. All is tight expect for
this shimmy. The shimmy does
lessen when letting my foot of the
accelerator at around 45-47, but still
there. Also the car shimmys side to
side at 45, but not together as one
when the wheel shimmys.