Ok the repair idea did not fix he problem.
Re-saving with minor change did not work either.
pulling my hair out did not do the trick either....
Removing 17 out of 86 photos that were freezing during rendering worked, so not satisfied I did the following:
Used the slideshow creator, first just the offending pics. then added original, and 're-saved' ones, and using Bluray authoring option all rendered perfectly!
Then to make sure it was not a fluke I took the mpg and stuck it in the original project, sans the offenders, renders perfectly.
What do you think?