keyboard input ignored after opening editor window via Ctrl-N/Ctrl-Shift-N

This is an issue that has reappeared in build 5745. Often (but not every time), when I use Ctrl-N or Ctrl-Shift-N to open a new editor windor for a class/file, the caret appears briefly in the new editor window and then disappears. At this point, all keyboard entry is ignored; I have to use the mouse, or Alt-Tab twice before I can use the keyboard to do anything. As somebody who relies on the keyboard, I find this very annoying.

Is anybody else seeing this behavior? Given the intermittent nature of the problem, I'm wondering if there some race condition at play here. (I do have a dual-CPU box, if that matters.)