Here, download this file, and have VA run it, instead of VA Left Clicking.
The only thing it will do is hit the Left Mouse button.
So, if VA can move the mouse into the correct position, this will click the button.
I also have problems with mouse actions with VA. What I think happens is, that VA is making it's self the active window for a split second, and that causes the issue. At least it use to do that, not sure what it's doing now. On some programs, I can't have VA interact with menu's at all. So, had to find another way.
If there is another solution with just VA, I don't know what it is. This might work, or not. It's simple though.
Maybe one of the other guys might have a better solution, let me know if this helps.
http://www.filedropper.com/leftclick