So I have my view setup in IB such that this text label aligns with the top of the thumbnail via constraints.
TomSwift thanks for your answer, i really struggled with this issue.
If someone is still getting weird behaviour, i had to change:
intrinsicContentSize = CGSizeMake( inaccurateSize.width, accurateHeight);
to
intrinsicContentSize = CGSizeMake( inaccurateSize.width, accurateHeight * 2);
then it worked like charm.