ptr_for_handle() seems to be the problem here. Sometimes it returns NULL for a valid TEXT handle. This might be an engine bug.

The problem also occurs in this little script:
Code:
#include <acknex.h>

PANEL* pnl1 =
{
	layer = 2;
}

void main()
{
	level_load(NULL);
	
	int i;
	for (i = 0; i < 3; i++)
	{
		TEXT* my_txt = txt_create(1,10);
		var my_handle = handle(my_txt);
		my_txt = ptr_for_handle(my_handle);
		
		if (!my_txt)
		{
			printf("NULL pointer (handle: %i | hbyte: %i)",
				my_handle, my_handle >> 14);
		}
		else
		{
			printf("pointer OK (handle: %i | hbyte: %i)",
				my_handle, my_handle >> 14);
		}
	}
}

The problem is somehow related to global PANELs and TEXTs and their layers. With one PANEL ptr_for_handle() fails only one time in the above script. Adding two more PANELs on layer 2 will make ptr_for_handle() fail three times instead.