Before I start, Availability has never been fantastic with AirAsia, but MEL-KUL seems to have the best. Just use Adioso, but I dont think they go to deep into the travel period. http://adioso.com/au/australia-to-kul.html
MEL/OOL/PER to KUL $119
PER to Bali $119
TRAVEL: 14th Jan-30th April 2010
ENDS: 2am 7th September
Pretty good deal esp if you missed out on the previous Air Asia sale. Looks like there are plenty of dates available from Melbourne:
http://adioso.com/au/mel-to-kul.html