Disappearing field in Registration Area...

Hi,
You can't use the state field without the country field unfortunately. You should publish the country field. For now, you can unpublish all unneeded zones and keep only the USA in the country field and the state dropdown will display the USA states.

You're right there was still an increasePerf call on the install.hiakshop.php file. We will remove it.
We will keep the second one in the import.php file and the function definition. At install it's not possible, but during the import the system should only crash once and if you refresh the page it should work as it will be automatically disabled. Remember that this increasePerf function is something useful on some hosting companies which restrict the memory usage and execution time out to values which are too low. We need to keep it on process intensive tasks like the import. During install, we can remove it as it's not too processing intensive and should be under the minimum values hosting companies put. We had it there just as a precaution.

You don't need to unpublish the states, just the countries. So around 200 entries.
You can filter the zones by type by selecting countries on the top right filters of the listing of zones.

You can also run the query "UPDATE jos_hikashop_zone SET zone_published=0" in your phpmyadmin to unpublish all the zones at once.