It has already been reported that the game will crash if you click the claimants button for a title when a list of claimants for a different title is already displayed. Some have also claimed that all you need to do the crash the game is double-click the claimants button. Paradox staff are aware of the problem, but I don't know if that's the case for QA as they have not acknowledged the bug reports regarding this issue.
We are aware of the CTD that happens when using the claimant list and have responded to threads on the issue before, perhaps not just very recently. I think one of the programmers looked at this the other day or so. So hopefully it will get fixed soon™.
Cheers for posting though.