I did say "at best" At worst it could damage your TV. So knock on wood.

What happens if you eliminate the sleep out of the whole process? How about:

1. just switching the switcher back and forth (with and without waiting a while)
2. unplug and re-plug DVI switcher while still swtiched to "Mac" input
3. switch to other, unplug, switch back, re-plug?

And also, how about sleep and wake without touching the switcher at all?

If you've covered any of these already, I'll have to apologize. I was trying to eat and drink a really strong beer at the same time.