I've set permission for 'regular users' to be able to delete their own posts but the remove button doesn't show up on any of the templates, not even on the SMF default template.
I can see it just fine when logged in as admin.
Any ideas why that could be?
Check Admin / Generate Reports / Board Permissions
This page will allow you to see where they have the permissions and where they may not. Some boards may be set up to use local board permissions, meaning you may have to allow the permission there (Admin / Permissions / Permissions by Board) as well as in the global permission section. Also make sure the member or members are not in any group that denies the permission.
Thank you for your help, I had never used the Generate report option. I didn't change anything but now everything seems to work just fine.