A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
A few questions and a couple of guesses.
Can you give us a link to the specific template you are trying to work with? It's easier to figure out things when you can really see what's going on.
What is the specific error you get when you change a sheet's name? I suspect it is #REF! but we need to be sure.
My GUESS is that the template has the worksheet names 'hard coded' into it, either in macros or through the use of INDIRECT() functions or dynamic named ranges that refer to specific sheets. The minute you change the name of a sheet they are looking for, you're going to start seeing errors. The 'fix' for those situations is to find and change every reference to the sheet(s) you wish to rename, and with templates put up for public use you are quite often facing the problem of having to unprotect worksheets that have their formulas 'locked' by way of applying protection to the worksheets, or even the workbook.
If you can't provide a link to the source of the template, perhaps you can upload a copy of it to one of these free file hosting sites and then provide the link to the file that they give you after the upload:
MediaFire: http://www.mediafire.com
Windows Live Skydrive: http://skydrive.live.com
FileFactory: http://www.filefactory.com
FileSavr: http://www.filesavr.com
FileDropper: http://www.filedropper.com
RapidShare: http://www.rapidshare.com
Box.Net: http://www.box.net/files