I agree it's kinda goofy to have the option to Advance Analyze when the movie is less than 5gb.
With that being said, here's what I do for DVD5 disks, for all those who already own Nero and want to get their money's worth. (rather than using Decrypter, no offense, I just like to use the products I paid so much for to the fullest extent.)
When I pop in a DVD I right click on it in My Computer and check the Properites. If it's less than 4.7gb then I right click, Explore and copy the folders within the DVD to a new folder on my HD. (Usually a Video_TS and Audio_TS). This takes about 5-15 min. Then open burning ROM, select New DVD-Video Compilation. Drag over your Video_TS files and burn. Done.
Hope somebody can get some use out of it.