I hope nobody else has this problem, but just in case, here’s the thing I had to diagnose this afternoon: a few select boxes (those things that drop down a list of options and you choose one) were immediately closing themselves in IE9, which prevented changing their options. It only happened in IE, but I noticed the same elements were causing strange behavior in the Chrome developer tools—computed styles couldn’t be expanded, the attribute checkboxes were flickering, and the JS console was slow and stuttery when opening it with ESC). That behavior tipped me off that there was probably something strange happening in our code, not just in IE. Turns out that to automatically check a text input for matching content in our database, someone had implemented a jQuery function to run every 250ms, and that’s somehow interfering with the select elements. It’s not solved yet, so look forward to an update after I find a solution that (hopefully!) keeps all the functionality intact.