Burning Software vs. DVD-R media vs. DVD Players

Question

Is it the Media, or the Messenger?
Am curious to see how my recent experience with burner/media/player compatibility stacks up to other people's:
I discovered (to my dismay) that a bunch of discs I'd created on both Maxell and Memorex DVD-R's (the Future Shop, 25-pc cake pack kind) would not play properly in two different Toshiba Players, yet played perfectly in a very low end Apex machine in the kids' playroom.
But what's got me more intrigued (and baffled) is the solution:
If I use the same lower-end media (the Maxell and/or Memorex 8x DVD-Rs), but burn them directly from iDVD using the ".dvdproj" file (instead of burning from Disk Utility using the ".img" Disk Image file I'd created earlier), everything plays fine in the standalone players.
OR: If I just upgrade the media (to Verbatim 8x DVD-R disks, which seem to have a much better reputation), but burn as I originally did (from Disk Utility using the ".img" Disk Image file), again, it's problem solved as far as the Toshiba home players are concerned.
I also tried other combinations (burning from Toast 6.11 at 4x and at 1x speeds) on both kinds of disks, and again all was well. So the one combination that proved the flakiest was using the more standard grade media and Disk Utility together. Using slightly better media (which I can understand) OR burning from something other than Disk Utility (which is what's making me scratch my head) both seem to improve the situation.
So how come burning from Toast (which uses that VIDEO_TS folder from the mounted disk image file), even on the "lower end" media, makes a disk which plays fine in the Toshibas, whereas burning from Disk Utility (which lets you simply select the unmounted disk image file itself) produces a no-go-on-some-players disk, yet works fine with a slightly higher-end disk?
Am I just banging my head against the welcome-to-DVD-authoring-in-2005 wall of randomness?
Or has anyone else found that there is generally something less stable about a DVD burned with Disk Utility, vs. one burned with either Toast or directly from iDVD -- all other things being equal?
While I'm at it, some related questions:
The specs for the SuperDrive in my dual 1.8 G5 PowerMac say that 4x is its maximum DVD burning speed. Would there be any advantage to my trying to buy only 4x (or slower) blank disks -- which some seem to say are more reliable?
Similarly, when burning with Toast, is there any theoretical advantage (in terms of maximum compatibility with the widest range of home players) to selecting the 1x burning speed, rather than leaving the "Best" default setting untouched?
Finally, as far as different brands of home players go, is Toshiba considered one of the more finicky when it comes to non-commercial DVDs? Are there other brands with either good or bad reputations in this regard, or is it just an ever-changing, model-by-model kind of issue?
Thanks for reading (sorry for the length).

Answer 1

Just got around to reading this thread, and wanted to report that I have experienced my second time of trouble with my toshiba DVD player.
As others have noted, the DVD project seemed great in iMovie and preview.
I then made the disk image and it saved fine, so I burned my DVDs. Thought I would check it out on the player. Everything seemed good until I reached one segment where the video sound suddenly seemed to mute, leaving the background audio track louder than it should be--as if the muted segments had switched places to produce the opposite effect of what I had set up. So, I went back to my iMac and played the disk image--perfect!
Then, I went down to my Sony DVD player, and, of course, my just-burned DVD played perfectly!
The last time this happened, I went crazy trying to 'fix' it --trying to re-edit the movie, wasting disks thinking they were bad--before I realized it was the player.
For some reason, the toshiba player doesn't read the audio tracks correctly--and drops or changes only some segments.
I had always thought Toshiba was a good brand. We have a combo TV-VCR small unit in the bedroom. It has always performed well, so we thought the DVD player would be good too, and it is, but only for the commercial DVDs. (Thanks for the explanation about them, that they are pressed not burned so of course they are more durable).
I am going to Best Buy to get an inexpensive Sony DVD player. I am tried of the inconsistency of the Toshiba!