I just upgraded to Mtn Lion from Snow Leopard. One difference is I used to be able to export a QT movie out of AE that was uncompressed. Now that option is gone, have to compress it with one of the many options. I have a sound added so I can't export stills. The uncompressed will give me more options as i create different formats. Thanks!!
Quicktime installed 10.2
Mac OS 10.8.3 and 7
After Effects CS3
Steven Houtzager