Ya.... you gotta use Shrink for that. Rip both titles to the hard disk and then use the "re-author" mode of Shrink to combine both titles and (if needed) compress them to the size to fit a single DVD5. Then, if you lack Nero, take that new output folder and bring it back into CloneDVD2 to burn it.
I did just that with "Gone With The Wind" - with good success.
When using DVDShrink to accomplish this, don't you loose all the "extras" and will the resulting DVD be a "Combined" movie of the two parts - or will there be a Chapter or some other "break" between the "movies"?
The instructions indicate that the two moves will be "joined" and becomeone movie after the process has completed. That's fine if that was what was desired and isn't if the integrity of two movies is desired. In that case Nero Vision will allow the two movies to be placed on a single DVD and maintain a "Break" between the two - and you can create menues to do this..