To my knowledge there aren't any other XMLTV grabbers for Australia.. I just tried removing the capture cards and re-adding them. Nothing. I also changed the "offset" (the one that tells you not to use it unless you have to). It also did nothing.
I have the same problem with d1xmltv grabber every time daylight savings begins or ends. the time zones are out by an hour usually for 1 week or 2. I play around with the d1xmltv grabber config for a while (there's a timezone offset parameter) until I get it right. It involves clearing out and reloading the EPG data a few times. Eventually I get the 7 o'clock news in the right time slot. And then I pour myself a big whiskey....
...and wait until it all goes wrong again ( usually about 1 week later), at which point I go in and revert to the original setting in the config file.
I'm another OzTivo guide user, never had any problems. I use the OzTivo Extreme Grabber (found on xpmediacentre.com.au) and call that in the UpdateEPG.bat to grab the fresh data every time the EPG is loaded.
If you're interested I can post some more detailed setup instructions.