My first and only character is about level 15 Healer/Thief, traps skill level 1.

Created a new world. Ransacked the first level. Searched everywhere several times.
But it's impossible to find a way to go downstairs. There is no staircase for level 2.

Archived the complete directory of the game for further investigation.

tar cvzf DinsCurse_no_staircase_to_level2.tgz ~/.local/DinsCurse

Can place it on my own server or send in an email, it's very small.

ls -la ~/DinsCurse_no_staircase_to_level2.tgz
-rw-r--r-- 1 frank frank 31130 Oct 12 08:16 /home/frank/DinsCurse_no_staircase_to_level2.tgz

If there isn't any hidden room and I just have been unable to locate it, this is serious bug.

have fun,
Frank