the first question would be: did you create your sliedshow in 1080? if not - your programm will be upscaled that wont result in good, crispy quality.
another point: toast encoding is no high-quality encoding - so if you would like to have a nice picture I would advice to use adobe encore for BD-authoring and do the encoding using adobe media encoder, apple compressor or even better.
another issue is your BD-player or display. I don´t know what you´ve done: 1080interlaced or 1080progressive.
depending on your player-setting it wont be displayed correct on screen - maybe it would be deinterlaced where it is progressive or wise versa.
Daniel, I'm surprised what you say about Toast's BD encoding. I'm dragging to Toast 10 a ProRes HQ 422 QT .mov file (1920 X 1080i) and getting great BD's. They look fantastic and even examined close up on a big screen there is no noise and a great picture. Are saying that a BD encoded in Encore would be even better?