Office 2007 and windows XP

I have a .xlam file which contains macros which I wish to load hen excel
starts

It is in the folder
C:\Documents and Settings\USERNAME\Application Data\Microsoft\Excel\XLSTART

and it used to load with excel but it has stopped loading.

What has changed ? or how do I get it to autoload again?

(a regular xls file in the same folder loads ok so its something to do with
the file type?)

Thanks
--
Patrick