Had a dead laptop that was apparently still under covered under Best Buy's protection plan!

Got a letter saying the plan was expiring, so I brought it in & they gave me a new one, so I'm back to doing reauthors on PC again! Still haven't found a really good way to do it on Mac without losing a ton of quality on the picture.
I've got everything reinstalled other than various ripping software that I'm sure will be needed with Twilight and the more tricky rips. The only problem now is trying to remember all the settings on everything, I think I have everything all set & I'm burning a disc now to see.
Couple quick questions though...
Going to attempt trying to do reauthors in surround sound rather than just 2 channel stereo for the first time later this week. Can someone point me to the settings I need for Clier's AC3tool to keep the 5.1? The tool seems pretty straight forward, but when I try to load the 5.1 wav into GoldWave it doesn't know what to do with it. (So maybe it's the settings I need to tell GoldWave on import rather than Clier's?) And once I get it to load, it's just the same as normal as far as the reauthor goes right? Or is there anything else I need to do?
Second and more important question that I'm sure was answered somewhere but I probably missed it, my biggest complaint when I finish up a reauthor is that the audio on the DVD is much quieter than a normal DVD. I typically have the volume at 15 on the TV for watching TV or DVD but with my reauthors I end up having to turn it up to around 45 or 50. Not the end of the world, but sure can scare the pants off you if you forget to turn it down before switching back to watch something else.
Just thought of one more thing. How can I get DVD Decrypter to stop throwing error messages when I close the program? I have this problem on every machine I've installed it on.
The errors are:
Failed to set data for "
Failed to set data for 'DVDDecrypterPlayDVDMovieOnArrival'
Failed to set data for " (sometimes this last one repeats a few times)