Believe it or not the problem righted itself after a day of blank guide... not exactly sure what was going on at the time but it certainly fixed itself as I didn't do anything haha!

I did rerun setup and it started working again :) Thanks All!

I just discovered this too.

Have a look in the shepherd log. I had a missing dependency, plus I had to re-run the config:
tv_grab_au --configure

to reconfigure and then I had to update a couple of my channel names (I did through mythweb).

After all this the data is there. If you need it to rerun using the existing xml file, then run:
mythfilldatabase -- --reoutput

If you need to change the channel names like I did, you might also need to do a find and replace on the output.xmltv file for the channel id's (or just wait for it to run again).

Ben