Bootmii crashes if SD card removed

I'm using bootmii as IOS, and when I removed the SD card and pressed the SD icon on the main bootmii menu, it came up with

"Failed to read dir"

then a prompt "->"

No button on the GC controller, or power/reset/eject did anything.

Does it unfreeze if you replace the SD card?

nope, tried everything, had to hard reset

Tried to recreate the issue, but replacing the sd card caused it to unfreeze.