TimeTrace Error: GetObjectKeys without criteria

Using v8.1.1. I've got a bunch of columns set to IsToWatch and the history database archiving off the dialogwatch tables for entries 14 days or older. I've also got the History Database entered in the TimeTrace Databases section of designer so when I look at TimeTrace in Manager, I can see the entries that are older than 14 days. This works great for Person objects but I'm having a problem with the assignment tables and TimeTrace. When I select a Person in Manager and then click Assign System Role and then show the TimeTrace window, I can see entries going back to the start but for the older ones, when I click on the entry, instead of showing me a preview, I get an Error popup that says 'GetObjectKeys without criteria'. If I select a newer one that hasn't been archived to the HistoryDB yet, I get the preview. So it seems I get errors on TimeTrace entries that have been archived to the History DB. Is there anything I can do to resolve this issue?