record sound and mp4a

[Kurt Kaufman]

When I query the recordformats  (Rev. 1.1.1; QuickTime 6.1; Mac OS X 
10.2.4) the list includes
MPEG-4 Audio,mp4a

However, when I try the following:
record sound file "testmp4a" as "mp4a"

QuickTime cannot open the recorded file.  Isn't the MPEG-4 a legitimate 
sound file format?

Thanks, Kurt