I've seen quite a few others reported Safari's issue here. However, I myself, have no Safari issue. On the other hand. I have Finder UI hang or DVDFab stop encoding (but not hang) issue. In the last 2 weeks, if Finder freeze, I relaunch Finder. If DVDFab stop functioning, I restart DVDFab. But today, DVDFab stop encoding again (in the middle of the process). I suddenly think how about if I quite Safari (I usually keep Safari open 24/7). And bingo, all strange issue gone. DVDFab continue to encode. No need to restart, no freeze, nothing. Even I don't know why Safari has any relationship to a video encoding software. But at least I proved that Safari is the source of the issue (in my case). If anyone has any strange issue in HS. You may try something totally unrelated. And at least try stop using Safari.