Avi2Dvd

The AVI might have AC3 sound. Load the AVI with VirtualDub and do file__file information. 

If it is so, you need to demux it (File___save wav but save it "audio.AC3", and use that AC3 sound for your authoring purposes (the resulting of the 'blank audio' conversion will be a 'mute mpg' (if so, de-multiplex the M2V from it) or, directly and more correctly, a M2V file).

When you're ripping the movie to the HDD, you have the option of burning the files to a dual layer disk or shrinking the files to fit a standard blank disk. 

When you're burning a dual layer (8.5 GB disk) buy some Verbatim brand DVD+R DL disks. 

Use ImgBurn > 'Write files/folders to disk', browse to the folder and burn the new disk. 

While you're shrinking the files to fit a standard blank disk, run DVD Shrink >'Open Files' and browse to the folder. 

Click 'Backup' and choose to output the shrinked files to a new folder. 

Run ImgBurn > 'Write files/folders to disk', browse to the new folder and burn the new disk.

Avi2DVD will make the size right. That might not be the problem. Reburn it.