Burn has never failed me, and has performed better than Toast on multiple occasions. With Burn though, you will need to select 'Copy' and then drag the images you want, into the window and then click Burn.
Its that simple.
Now if you want to actually have a slideshow on you DVD, you will need to use yet another App, to build the slideshow, then Burn that slideshow to DVD.
I use to use iDVD for this, but Keynote should do the trick too.