Philips DVD-R problems (I think)

I thought I’d solved this problem a while ago by reading these forums, but the more I read the more befuddled I get. I have at least 5 tabs open and have closed many more (on my firefox browser as I try to read around)
I have burned some dvd’s well, they were converted from avi. to vob files with winAVI, and the end result was fine.
But now I just seem to be stumbling. The quality of the output is poor.
pixelisation, sound out of synch and even some of the shows are missing near the end of the DVD.
By the fact it’s only just occured I’m guessing it’s going to be user error [what is it they say “garbage in garbage out” :confused: ] I don’t know what information is relevant or what I need to be doing now!!
I am using
Philip’s dvd-r discs (though I also have a Tesco DVD-RW which seems to be where the prblems started occuring, even when I switched back to the Philips)
I have a
HL-DT-ST DVDRAM GSA E40N
I convert avi’s with winavi and burn them with the nero smart start for us thickies. I even try to set the burn rate to less than what the CD is and always get Nero to check the speed first.
I have watched most of these avi’s fine on my computer so that would lead me to belive it is my conversion techniques or burning methods.
I have read articles on updatiing firmware, dvdshrink, and checking the disk speeds, but the more I read the more confused I get :frowning:
Any pointers, post to other threads I have missed by a mile or a slap around the face with a wet fish, as long as it helps, would be appreciated.

Thanks again

MrJuggles