[dnanian]

Thanks for the additional information. As I said above, this pretty much confirms what I feared: 10.4.8 has a bug, and -- unfortunately -- its intermittent nature causes some "mystery" fixes (like a combo update application) to "look" like it works, but it doesn't.

The only fix for this at present is to go back to 10.4.7. We've got some ways to "shrink the window" where the bug happens (which has to do with screen updates), which should help to minimize the effect. But we can only do so much, alas.