if the boundary change was in 2003 and the last election was in 2004, therefore there has not been a new boundary change.
Ie if you were in boothby in 2004 you would still be in boothby in 2007. That as my point.
Regarding the ten years rule, It is actually more on the lines of every ten years OR if enrolment levels in a seat or state drop/raise to +/-10 or 15 of the national average or something. I prolly should of clarified that but well eh

SA dropping below a whole quota in 2003 (and qld having a surplus quota) resulted in a change, if that had not occurred a redistribution would of happened if it came to ten years without one.
pre-edit- i could be wrong here - ten years could be the US electoral college one, maybe we are 7 or 8 years or something. I might go check.
Regarding changes to the act to try and stop parties getting 51% and losing, SA has tried that with our fairness clause, and while there has not been a close enough election yet to test it working, I dont really like it, for one it results in a redistribution every electoral cycle, which so far has only had the effect of punishing well performing local members by cutting their margin.
The only way to prevent it is either have proportional voting: seats = vote%/x, or the next best thing is having one vote one value (which we do) and having an independant electoral commission to ensure no gerry mandering (which we also have). I dont think we can do much more without going down the path of proportional representation.