Disorganised, unpredictable (6)
I believe the answer is:
scatty
This clue is a double definition.
'disorganised' is the first definition.
(scatty means disorganised or absent-minded)
'unpredictable' is the second definition.
(I've seen this before)
(Other definitions for scatty that I've seen before include "Informally crazy or muddle-headed - like jazz singer?" , "Forgetful and lacking focus" , "Slangily crazy or scatterbrained" , "Bird-witted" , "dizzy" .)