Why do my scanned photos revert to original rotation when a create a slideshow?

Depends on to what extent the exif file is preserved.

What application/s are you using?

I may have a similar problem: I had album photos professionally scanned to a DVD, then imported them to iphoto and added dates and captions. When I tried to burn the now re-organized and captioned iphoto album onto a new CD, what got copied was the originial jpg number, and the original order. How can I get my organized album onto a CD without its reverting back?