I experienced the same problem with the genie and the white knight, i did however, find a solution.

This happened:

1. I fight the genie with the white knight, and kill him. He explodes, money drops. etc.

2. I try to move. Crash (If it is relevant, i had the acid debuff on me when the game crashed).

3. I reload the game and hit continue, having to restart the boss level.

4. I fight the genie again. However, the genie appears to summon 2 scarabs from the round metal thing in the middle instead of 1 now.

5. The genie dies.

6. Instead of moving right away, i skip turns until my acid debuff wears off (i am, yet again unsure wether the acid debuff has anything to do with the crash or not)

7. Everything goes fine and i can enter the dungeon.

Note: the first time i did this the game stuck at "Floor Cleared" when i left the genie's lair. I fixed this by simply rebooting my Ipod Touch.

I am using an Ipod Touch 3rd gen 32GB, with OS 4.1.

Date: 26th of August 2011.