Windows 7: Burning avi results in DVD with no sound. New Problem.

I build my own PC's, desktops anyway. This isnt my first try at burning DVD's.This started about 10 or so days ago. I drag and drop the avi to Win DVD Maker . I can watch "Preview" and get sound everytime. Hit "Burn" and when everything is finished , I play the DVD to test it and NO SOUND ! Almost all the video files I burn to DVD are avi. I have done this hundreds of times. This is a new and recent event. I tried to google this and I see a bunch of the same trouble back in 2009 but nothing recent. Im running Windows 7 Pro 64bit.
Im tempted to run system restore. Before I do this I wanted to see if anyone has any answers. Please dont suggest imgburn or Nero or any other software. I want to know what happened to my system as it sits. Please, any help is greatly appreciated.



Here are my system specs :
ASUS M4A87TD EVO
AMD Phenom II X6 1100BE 3.3ghz
16GB G.SKILL DDR3 1333
SAMSUNG 830 Series SSD 2.5" 256GB SATA ,OS etc...
WD 1.5TB 7200rpm, Downloads & photos & videos
ASUS HD6950 2GB MOD to 6970
PIONEER BDC-202 BD-ROM
NZXT HALE90-850-M PSU
NZXT M-59 Case
SAMSUNG 40in LED 1080P 120Hz
Bose Companion® 5 multimedia speaker system
Windows 7 Professional 64bit
WINDOWS EXPERIENCE INDEX : 7.5

Try DVD Flick. avi works well with it. DVD Flick

Suggest to read the instructions first.

" Please don't suggest imgburn or Nero or any other software. I want to know what happened to my system as it sits. Please, any help is greatly appreciated. "

I'm fully aware of all the DVD burning software available . I just want some help with what I already have. It was working 2 weeks ago and now its not giving sound when burning avi files. I burned VOB files and sound was fine . Honestly , I'm thinking some update has had this effect and maybe a restore will work, maybe it wont. Before I start screwing around with sys restore, I thought I'd look here.

Did you make any changes to your system software-wise? Perhaps it's a possibility that a codec update or a pack screwed something up.

Also, could you write down the details of the audio stream from some of those files that failed to burn properly? My guess is that it's MP3 since your files are in .avi but I want to check anyway.

I'm thinking the same thing, but not any changes made by me. I seem to remember an update recently but I will have to root out the problem myself. I was hoping that I wasn't the only one......Thanks for the reply