You are using a Panda3D version which is about one year older than the Panda3D version I used for compiling. You should report such deviations.
On the other hand it seems like the Panda3D snapshot builds are no longer available for download. Hmmm, you might try and use Panda3D 1.7.1 SDK, or compile yourself.
My fault. A .pyd file is nothing but a .dll which has been renamed. Old Python versions picked up libs with both filename extensions. Python 2.6 only picks up .pyd, if not loading the .dll directly (which is what Panda3D does).