Kununurra was performing poorly for QantasLink. It was my understanding KNX was operated year round (1x weekly), upping to 2x weekly during the "Dry".
From the Qantas.com domestic routemap:
Important Information:
This service only operates direct in one direction from Perth to Kununurra. When travelling from Kununurra to Perth the flight is via Newman. This service will cease operating on 28 October 2006.
Cheers