Did you try the ASR files from my post #12?

You have a 3580 i see, which i think was a NA-only LMT device, basically a 3590 with an FM GTM35 Traffic Receiver instead of the HD digital GTM60. Explains why you want the AU map. I'm using 2014.20 on NA 3597, 265 & 40 and AU 3590, 3490, 3790, 2455, 2595, 255, 465, 50, 300 [puff, pant] with no problems. Do you have a problem elsewhere or only in Sydney, and if so is it only certain locations there? Are any of the images you tried original Garmin maps, i.e. does the Header show the Garmin P/No D248511AG036 or just 000-00000-00 at the end of the line indicating a MS or MI install?