I don't think DP7's "Dynamic Page" tweak works properly in XDPX. I installed today's update, edited and re-uploaded a web site created in DP7.

On the various PHP pages that used the tweak, the dynamic placeholder and footer object resized and relocated properly but the graphical background object named "my_background" (as per the tweak's documentation) didn't stretch the way it was supposed to. It just stayed the original size and the other two items extended below it.

Re-exporting via DP7 got things working properly again.