hello,
this bug is around for a while (since version 3.0) and it is really annoying. if you select a session in the sessionlist that has only the matched files option and then you click to another session that only had the orphans options both checkboxes will be checked - which is more than confusing. the problem works also the other way around: 1. orphans -> 2.matched
if you than choose another session in the list you get the question "do you want to save the changes you made?"
this is really bad