Hey guys, I'm new - as you can tell

I've got a question here..
Many of my friends have reported , or told (not to sound too formal

) me that they have seen, or found, some even have downloaded / bought a few , as they call them, Multi DVD's.
I, myself, am very familiar with the DivX format along with all other formats, my query is this.
I've used ConvertXtoDVD to create a 4.2(ish)GB DVD from 2 AVI files. These Multi DVD's contain 3 DVDs on the one disk, no Subs obviously, with a menu and at the same quality. If i try to use 3 AVI's with ConvertXtoDVD the output is roughly 5.5(ish)GB. Any ideas what I can do or use to sort this out?
Cheers guys, I know someone will have an answer
