AFAIK not yet. This bug is as old as harmattan and no one found a fix or at least the reason for the problem. And sadly it seems no one found out, where and how SMS are stored, so it is quite hard to investigate. What i wanted to try, when i get the problem next time is N9QT -> SMS-Backup -> delete all SMS -> and SMS-reimport, maybe this could help, but i did not have the problem since i deleted all SMS last time (about a week ago). Maybe you can try...