as shown here: is this a virus?
Im not showing any virus or malware but have buggy behavior
1. key command: Option-Tab (for window switching). I use it all the time and it always worked fine. Now, it works right when system boots but then stops working. When invoked, it kind of half flashes on screen but does not execute switch.
2. quick launch hover. again, it works right when system boots but then stops working. upon hover, not thumbnail shown.