UDF does not work on other computers even when appropriate add-in is installed

I have coded and tested an add-in for excel and it works well for my particular application. Using the user defined function in the add-in, I made a template file of sorts that you take and fill in the current data and save as a new name. Several other people in my office were interested in this functionality, so I saved the template and add-in on a network drive that is accessible by everyone in the office. The problem is that even when the add-in is installed on a co-worker's computer if they open a file that I have filled in with data, all of the places that use a UDF from the add-in show #NAME? errors. The document also wants to "update links" and if you follow the link it is trying to access the add-in that is installed on my local machine. The only thing that I can think of that would be a complication is that I am using Office 2007 and some of the other people have Office 2010.
Any ideas?
Thanks!