I’ve had a problem with projects from FCP X. The AAFs produced (with X2Pro) often include material at 44.1 (music generally) i.e the AAF contains mixed rates. Nuendo doesn’t automatically convert the 44.1 material, so it plays those clips fast. I can convert the clips in the pool, but then I have to manually reproduce any edits.
I tried opening one of these AAFs on Pro tools and it was fine - PT converted everything. I was then able to export this as a new trouble-free AAF, so I have a get-around. But I’d rather not have to go through the PT phase.