The problem can be pretty easily fixed:
Take the cradle apart by first removing the four sticky rubber pads on the bottom, then unscrewing all the screws. Carefully pry the two halves apart.
You will see the bottom half of the GP2X connector attatched with two screws and a clear plastic spacer, with a ribbon cable running down to the circuit board. Just remove those two screws and save them somewhere. You probably won't need them again.
Try putting the GP2X back into the cradle. It fits best if you angle the top of the GP2X a bit towards the rear of the cradle as you slide it in. If your cradle is like mine, it will slide easily now. The connector will remain attatched quite well despite not being screwed in, they aren't necessary to hold it. You might also try adding nylon washers underneath the screws and tightening them to varying tightnesses if the above doesn't work. Also check for plastic flashing surrounding the EXT connector on your second GP2X, pushing the sheilding into where the connector is supposed to fit.
Kinda lame, I know. If you still want an alternative cradle, this is the ultimate:
http://www.gp32x.de/board/index.php?showtopic=36597 Unfortunately, it is meant for the developer break-out board.