I think 21 and 88 are duplicates which are probably no longer used (in Melbourne, I used to get 21 ABC but don't these days).
So leaving that aside, cashie, you get guide data for every channel which you should except for GWN7.

At the oztivo end, we are currently sending out GWN7 guide data using the following tivoids:
S3-RegionalWA-GWN7 | 156653439
S3-RegionalWA-GWN7-2 | 124897547
S3-RegionalWA-GWN7-3 | 187916214
S3-RegionalWA-GWN7-4 | 186983668

If you are comfortable doing a little tinkering with your tivo can you please run the following
commands on your tivo :-
sed -e '79iputs "stations($trans,$num) = $val"' /hack/bin/station_debug.tcl > /var/tmp/station_debug2.tcl
chmod a+x /var/tmp/station_debug2.tcl
This creates a modified version of station_debug.tcl in /var/tmp/station_debug2.tcl.

Then run that modified version, sending the output into a temporary file (it will take about 1 minute):
/var/tmp/station_debug2.tcl > /var/tmp/station_debug2.out
and check the output for GWN7:
grep '2560,5)' /var/tmp/station_debug2.out

I expect you will only get one line of output, but if you do get more than that, it should give me more
tivoids that I can add for GWN7 (if they are not already in the list of four above).