What is "deciding" factor in successful production

[victoriabears]

I am prompted to post this, having seen criticism of media, then praise of same media.

So, we capture/edit/encode/author/burn, hope have not missed anything<g>.

Is it true that a faulty DVD, as in playability, can be created by any of the following:-

Crappy software/hardware
Bad housekeeping whilst processing any part of the project, eg: using internet/playing games at the same time.

I ask because I had only one bad burn, only whilst trying to be clever and print/use internet whilst burning.Printing really seems to be a bad boy.
Have used Power producer/windows movie maker/Tmpg Express/Tmpg Author/Nero(Only to burn)/media=Prodisc -R, HP + R , LG 4082B burner.
2500 Barton CPU/1gb ram/Ge2500 /ADVC300

What do we all/the experts think?

When we get a bad product can we honestly say we are all behaving whilst producing it at all stages?

[lordsmurf]

Yes, lots of factors can affect it.
But for some of us that test in ideal circumstances, bad media is bad media.