Yes and no, thats what we were trying to tell you, theres no setting in maya to govern this! When a avi comes in if it has no specified framerate most software asume its 29.97 fps. Maya will not set this period.
The renderer deals in frames whatever you try to tell it.
So you msut tell the software you imprt it to, to conform to another rate. Chak your manual on this.
Ps and playblast is a totaly differenbt story, you can even set compression on that not on output render tough, not that youd ever want to either, or ever want to render to avi in firstplace for any reason whatsoever.