@onkt. I am sorry to say that I can’t really help you with those older versions. I no longer provide support for them. Joomla 2.5 is no longer supported by Open Source Matters. Also, the sorting issue you are having has already been addressed by version 3.0+ editions of the software.
You really should consider upgrading to Joomla 3.4.1. JED no longer hosts extensions that are compatible with Joomla 2.5.
To get it working, you will need to purchase the current version of Easy Folder Listing Pro. I have added the version 3.1.9 tot he download list, for archival purposes. You may use that until you upgrade your Joomla version. If you email me, you can also receive a 30% discount coupon, since you are an existing customer.