I installed SP1 and tested the new AVI functions. You can see a lot more codecs in the 64 bit version. So this bug appears fixed.
But beware before upgrading! See this issue:
http://forums.ni.com/t5/LabVIEW/What-hapenned-to-the-MJPEG-codec-in-Vision-2012-SP1/td-p/2317262
http://www.medicollector.com