Hmm, playing Europa Glacier Mine (
http://kyouryuu.furvect.com/levels/eglacier.zip), fight your way to the Blue Key. When you get the Blue Key, descend downward and you'll get warped to a corner of that room, overlapping a Diamond Claw.
There are two triggers here. The first, located at cube 86, side 4 (86, 4), is "Light On" to (83, 2), (84, 2), (82, 2). The second, just below, is "Open Wall" on (66, 1), (69, 3), (64, 2). I think the first is probably the culprit because when the player is warped, you get stuck behind one of the walls that would have opened on the second trigger. Maybe there is something wrong with "Light On" triggers? Perhaps D2XWin32 in Entropy Level 2 was equating a "Light On" with your new "Teleport" message.
Also, suggestion. If the user goes to File and selects a HOG file with multiple missions from the "last five opened" region, and that HOG is already being read, DLE-XP should open the HOG as usual and present a listing of missions in the HOG. Currently, as DMB2 did, if you opened some level in descent2.hog, and then tried to open descent2.hog again from the File menu, nothing would occur.