Can't highlight

[Shanegrla]

Hi, has anybody ever experienced this problem? I highlight an area with the selector tool (or multi tool - doesn't matter how long or short of an area or region - and as I'm highlighting, I can see the region get dark like normal. But then, when I let go of the mouse, the highlight disappears! (Not the audio or midi that I'm trying to select, that stays fine. Just the dark highlight disappears. It just literally unhighlights after I let go of the mouse!) And then maybe after the 4th or 5th try, it finally works (the chosen area remains highlighted).

Also happens when I try using the grabber tool. The region just blinks black for a nanosecond and then unhighlights. Very weird.

It seems to be very random when this problem happens. Things will be working normally for weeks, and then for a couple days in a row, it will give me this headache. Any ideas as to what causes this? Could this be a Mac issue or a Pro Tools issue? When this happens, the mouse seems to work fine in other applications, so I'm leaning toward it being PT.

P.S. While I'm at it, on a related note, here's another little annoyance that occurs quite a bit. A lot of the time when I try to select a section of midi notes with the selector tool, the very first note (snapped to the grid) in the selection won't highlight for some reason. I have to start the selection one grid line before the spot I really wanted if I want to make sure it gets included in the selection. This also seems to be somewhat random. Sometimes the first note does get selected, sometimes not. At first I thought it might have something to do with notes that I pencil in work fine or something, but not the case. Just kinda random.

Any help would be appreciated.