Now, having said all that, the Bushwacker is actually fairly easy to fix, if you're prepared to hack the CR2 file with a text editor. I use EditPad Lite, myself, but you should be able to do this with any utility that has a global search-and-replace function.

Open the original Bushwacker.cr2 and replace all instances of Rthigh with rThigh. Note the capitalizations. Repeat this process with the following parts:

Lthigh --> lThigh
Rshin --> rShin
Lshin --> lShin
Rfoot --> rFoot
Lfoot --> lFoot

Save the modified CR2. Use a different filename if you don't want to overwrite the original.

Load the modified Bushwacker into Poser. Set the BODY's Scale to 100%, then drop the figure to the floor (Figure menu --> Drop to Floor, or CTRL-D).

Save the CR2 back to the Library. You're done. Note that in Pro Pack and P5 (I'm not sure about P4), saving the CR2 to the Library will strip out the embedded geometry and generate a new .obj file in the same folder.

Now, create a walk path, launch Walk Designer, and use the Figure Type button to load the CR2. Apply the walk. Then marvel at how silly a mech can look when it tries to walk like a human.