Looks like you are trying to install a WM 6.1/6.5 taskbar on a WM 6.5.1 or 6.5.3 version of WM (anything 23053 or later).
The only taskbar that I've seen that works on (at least some of these builds) is
http://forum.xda-developers.com/showthread.php?t=562251
Last I saw tsowens has said that he's not running 6.5.x yet so he hasn't created a taskbar for it.
More info:
http://forum.ppcgeeks.com/showthread...=65911&page=72