Tome zone slowdown

[ikarius]

Last night, Tome just went into no mans land for me. I finished up kor'pul, used rod of recall to exit, and went to derth, tried to enter, and it claimed repeatedly "there is no way out of this level here". I saved and exited, quit t-engine, restarted, loaded up my game, tried entering again, and it gave me that error once, then let me into derth on my second try.

Once I got into derth, movement was incredibly slow, and it actually left a copy of my character standing on the world map exit
I was clicking with mouse to move, and it would move a couple of squares and stop. I exited back out, and it's same thing on the world map. After experimenting a while, I determined that both Derth and the world map were running incredibly slowly, but other maps were fine. I backed up the save at this point, and tried an experiment; I deleted the saved maps of world map & derth, and went back in- and that cleared the problem. Is this known, or is there someplace I can zip the save directory with these broken zones and upload it?