Hi Tom,
I measured 215V, over the two terminals 4 and 6 on the opto, when the LED is off and .8V when the LED is on, so it seems to be working. I'm wondering if has something to do with the design of the opto, if it can take the votage spike, but I'd think that it would at least work once before breaking. Do you think a SCR would make any difference, like the C106D?
Thanks!