Kickstart installation self-starting without waiting for complete configuration

I have installed maybe like 20 instances of RL8.4, using kickstart configuration file, with always the same contents except the name/IP of the machine. All partition-related entries are commented out so the expected behavior is to stop at the main configuration window and let the user configure the storage manually. Yet at least 2 or 3 times already, the installation just continued by itself, auto-arranging the storage using LVM. It is hard to debug as after stopping the installation and running it once again from scratch, everything worked as expected. With the very same kickstart file.
I wonder whether anybody has experienced anything like that.
regards, Michal