So here's what I've got for you...
While studying in New Zealand last year I was forced to play region 4 DVDs and didn't particularly want to waste one of my five region changes, so I did a little research. Before I explain how to sort out this problem, let me first disclaim that from what I know there is some amount of risk involved with this procedure in flashing your DVD drive although I would add that in all of my searching of forums, I found no one that had any problems with this. The other key point is that flashing your drive will void your DVD drive's warranty... this being said, this process will enhance your burning speed, allow you to burn DVD-RWs, and my favorite, it will allow you to use Region X explained below.
If this doesn't scare you off (and let me say, it shouldn't as I have yet to find someone who has experienced problems) then heres what to do. First, download the hack from here:
http://macslash.org/article.pl?sid=03/12/15/1329226 NOTE: this is not the hack I used, so you are welcome to look around for something similar. WHILE FLASHING YOUR DRIVE, MAKE SURE THAT YOU ARE CONNECTD TO A POWER SOURCE AS RUNNING OUT OF POWER WHILE FLASHING COULD BE DEVESTATING. With this done download Region X from here:
http://xvi.rpc1.org/region.html and you are ready to go. What you can now have is a region free DVD player (this means that you can play region free DVDs, not that you can play DVDs from any region). What you can now do is when you insert a DVD of a different region, you will still be asked to change the region with a max of 5 changes, but now when you've done this just open region X and you will be able to choose to set the remaining changes left back to 5.
To sum this up: Flash your drive to make it region free, then use region X to keep setting your remaining region changes back to 5. There are certainly risks with this, but this worked great for me and there is little evidence online that this has provided a problem in the past.
Good luck with this, and I hope this helps.
-Avery