is it possible to get flv movies to freeze on the last frame

You can add a cue point to the time you want to pause than call a function:
var yourlistener:Object = new Object();
yourlistener.cuePoint = function(eventObject:Object):Void  {    
    if (eventObject.info.name == "yourCuePoint") {
        yourFunction() //you can pause or pause and load a still image here...
    };

that's brilliant, youll have to forgive my lack of skills, wher youve put you can pause or a load an image jhere, what command would I use to talk to the external flv to make it stop, lets say for example on the 359th frame?

You can add a cue point from the Parameters of FLVPlayer or directly from code. If you want it from code, here is a working example: I wrote it fast but It should work:

import fl.video.*;
import fl.video.MetadataEvent;
// create your cuepoint object
var pauseHere:Object = new Object(); 
// where do you want to place it? 359/video fps = yourTime in seconds
pauseHere.time = 1.5 ; 
pauseHere.name = "point1";
pauseHere.type = "actionscript";
// add your cuepoint object to flv player component
yourFLVInstance.addASCuePoint(pauseHere);  
// add your listener
yourFLVInstance.addEventListener(MetadataEvent.CUE_POINT, cueListener);
function cueListener(eventObject:MetadataEvent):void {
 trace("hello cue point");
 yourFLVInstance.pause();
}

Select allOpen in new window