Vista's DVD maker, Re-Rendering with MPEG2

I don't know why if I convert my video to MPEG2, Vista's DVD maker
insists on Re-Rendering it again anyway. I didn't have that problem
with my old PC (Using Sonic/Roxio, which BTW does not work with
Vista).
Also Vista takes twice as long to re-render it as my other software
does.
I really don't like to have to buy all new software.

Note: I tried installing Sonic but it removed my DVD drive!! (I had
to do a Vista rollback)

Vista's DVD cannot use mpeg2 using a separate audio file. (You get no
sound)
I have to render them into a single MPEG

Crzzy1