Fucked up (or, bowdlerized, fouled up) beyond all recognition (or beyond all repair, or beyond all reason, or beyond any recovery).
Unreliable; working only on an intermittent basis; likely due to malfunction.
Consisting of flakes or of small, loose masses; lying, or cleaving off, in flakes or layers; flakelike.
Unreliable; likely to make plans with others but then abandon those plans.