Cable import - terribly troublesome (11)
I believe the answer is:
problematic
'troublesome' is the definition.
(I've seen this before)
'cable import terribly' is the wordplay.
'terribly' is an anagram indicator.
'cable'+'import'='cableimport'
'cableimport' anagrammed gives 'PROBLEMATIC'.
(Other definitions for problematic that I've seen before include "Potentially difficult" , "Presenting difficulties" , "Baffling" , "Difficult; doubtful" , "tricky" .)