Name definition error when copying sheet

Hi,
I have a number of issues with my little project. I have some VB functions (from forums) and the main issue is when I copy the sheet, It keeps asking for me to rename them as they already exist. In addition, they then seem to be working sporadically.

I did reference some names within names and thought that may be part of the problem but I removed all those and it didn't fix it.

I've included my project and any help will stop me from tearing my hair out.
(I'm on a mac with office 2011)

Many thanks