Audio doesn't work in Internet Explorer

Audio is broken in Internet Explorer for almost all the sites I've seen using reCAPTCHA. The MP3 download option works, but the in-browser playback does not. Here's an example in the wild: http://bit.ly/1sOinb5 (The initial audio instructions play, but it stops before the numbers are spoken.) The only sites I've seen where audio works in IE appear to be using global keys (which we can no longer generate): http://bit.ly/1sOipjh http://bit.ly/1sOipjj Internet Explorer is getting a 400 Bad Request response code when requesting the audio file. Any ideas? -- You received this message because you are subscribed to the Google Groups "reCAPTCHA" group. To unsubscribe from this group and stop receiving emails from it, send an email to recaptcha+unsubscribe@googlegroups.com. To post to this group, send email to recaptcha@googlegroups.com. Visit this group at http://bit.ly/1dkFnYd. For more options, visit http://bit.ly/P65DvS.