Video embeds in lightboxes now all start playing when page loads — not when selected, in some browsers. This did not happen when site was posted. Appears to be a change in browsers—fine in Firefox 7.0.1, bad in Chrome 18.0.1025.142 and Safari 5.1.4 (6534.54.16).
Help! Site has been live for several months and worked fine, now some pages are a big mess.
Safari 5.0.6 works fine, so upgrades look like the problem.