I can't guarantee that that's your problem but it DID happen to
me with my e-type.  I bled everything fine but couldn't, for the life
of me, get the clutch bled.  I finally went back to the regular stuff
and had no problem.
   The reason I went to the silicone stuff was for it's corrosion
resistance but I discovered that just bleeding the regular stuff once
a year will do the same.  Regular fluid absorbs moisture over time so
the following is recommended,
  Bleed your system every year with new fluid.  Use enough to ensure
you've replaced all the old fluid.
  Use ALL the fluid in an opened can.  Once you've opened it, the
fluid begins absorbing moisture from the air.  Buy only small bottles
for top ups. It may not be as economical but it ensures you don't have
partially filled bottles hanging around.
 (By the way, in the aircraft maintenance industry we treat hydraulic
fluid the same way, for the same reasons)
  Happy Jagging!