[Koha] Wrong Due Date - upgrade questions

Hello, We have Koha 2.2.4 installed and working in our library. Recently it stopped giving the correct due date and it has to be manually edited for each issue. I haven't been able to find a setting that changes the amount of time a book is issued for. I'm planning on upgrading the system to 2.2.5 soon. Should I just wait to see if that resolves my problem? Before I update, I want to create a complete clone of our Koha library system on another server (for redundancy and backup). What is the best way of going about this.