Barsoomer
I think your suggestion of Perchlorate involvement in this great mystery might be on the right track. Perhaps the strange behaviour of the TEGA instrument is part of the enigma. Perhaps we are totally wrong in trying to interpret what we see on Mars as a subset ofn extreme environment on Earth and not seeing that we could actually be looking at a totally different microenvironment to any on Earth.
Suppose the SODs; the Perchlorate; the dryness of the surface in the presence of copious water both below and above the surface; the abnormal atmospheric pressure that just happens to allow liquid water presence under certain triple point conditions; the visual damp appearance of the surfaces at meridiani; gusev and even on the phoenix scoop and OM images; are all trying to tell us that there is an "unearthly" water balance system that will always confound us if we try to explain it totally in Earth terms, using Earth instrumentation and throwing out any suggestions of moisture that our eyes continually suggest has been there recently.
A planet that has evolved totally differently to Earth and has many features unlike Earth must have some differences in its micro-geology and dare I say, its Biology that do not mimic Earth.
I think the discussion here is finally getting to see the reality of Mars close up.
Winston