Inconsistent Macro Security
 

I have been using Excel 2007 for a few months now, and am unable to
understand why sometimes I get a pre-2007 style Security Notice pop-up asking
me to select to enable or disable macros when opening a file, while other
times I get the 2007 version which is a Security Warning, located between the
ribbon and the formula bar. To make things more complicated, others opening
the same files, get different results. For example I might get the pre-2007
pop-up on file ABC.xls. My colleague, when opening the same file, gets the
2007 Security Warning. Yet our Macro Security is set the same (Disable all
macros with notification). I should add that these files are Excel 2000
files, as all users on the netowrk are not yet up to the 2007 standard,
however the colleague in the example and myself are obviously using 2007.

Can anyone explain the reason for these inconsistencies?