I just installed 7.2.1 on my site.
When I first brought it up every other message in some of the forum was BLACK, couldn't see what was there, but if you click on it teh topic would come up. It would not go BLACK again. If fact some of the other returned to normal.
I tried a "Mark all read" and that seemed to cure,
But still some users are reporting it's still happening.
The site is Barnegat Fishin' Hole