That's on purpose to increase frame rate on the emulator. It sucks anyway...it has bugs in some many areas and is dog slow...i don't consider the emulator's software renderer to be useful for development. However, if you really want to, you can add a single line of OpenGL code right after creating the FrameBuffer that should give you perspective correction:
gl10.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
...with gl10 being the gl context. Usually, i don't encourage people to mix jPCT-AE with pure GL, but in this case, it shouldn't hurt.