One of my CF7 forms didn't work so well today. The date field did not work in IE 10.0.9200.16635 or Firefox 22.0. Worked fine in Chrome 28.0.1500.95m.
Would not send form because it could not validate the date format in the date field.
One complication is that I just loaded WP 3.6, so not sure if that has anything to do with it.
Could use some direction on where to start to identify the problem.