Refer to this post:
<!-- m --><a class="postlink" href="http://forum.zdoom.org/potato.php?t=9189">http://forum.zdoom.org/potato.php?t=9189</a><!-- m -->
In addition to that bug, the effect of the teleportation is always the same. However in Vavoom, the effect of the "Shadow Armor" makes the teleportation effect semi-transparent.
Edit: Updated version number