I'm completely baffled now. I left my preferences set to plain text, and tried to quote a picture someone else posted in a different thread. I can see the original fine, but my quote looks like this:

FanFiltration said:
http://www.sixtiesposters.com/images/aor2.75hb.jpg" width="285" height="432" />

How about The San Francisco Mime Troupe?

I didn't change the html at all. Also, when I do this same exercise with my preferences set to advanced editor, the quote works fine.

???

EDIT: Here's the exact same quote with the advanced editor turned on.

FanFiltration said:

How about The San Francisco Mime Troupe?

I think I broke the internets.