Why? - Back Button Focus + Auto Focus Lock = Auto Record

[rockychocbill]

Hi folks,
I have back button focus enabled on my 600D. When I'm in movie mode and get a focus lock the camera automatically starts recording. I have recording On/Off mapped the shutter button, so this is super annoying. I won't be using auto-focus all the time when shooting movies, but it's nice to use sometimes. I just don't want the clip to start recording right away. Any idea how I can stop this from occurring?

Thanks,
Bill