OS? Version of ID? All files, or just this one?
Did you try replacing the prefs, or just assume it wouldn't help?
I assumed it wouldn’t help based on other comments. Using Mac OS X 10.9.3, ID CSS 6 version 8.
I just logged out and then logged in and the problem cleared up but did the same thing before and it cleared up and then came back. Any ideas why this is intermittent?
Same thing happened again, after logging out and logging in, finding that the selection tool worked properly, it no longer does.