Personal.xlsb problems

[VBA_Newb]

If I open xl2007 via the excel.exe (or shortcut) it will load the macros
contained in the personal.xlsb file. However, if I click on an existing .xlsx
file, the personal.xlsb file is not loaded (not even hidden). I checked my
add-ins to ensure that the personal.xlsb file is disabled (thinking excel
might have thought it was corrupt), but it doesn't show disabled.

So, why does xl2007 load the macros if I open a new workbook, but not when I
open an existing workbook?

Thanks!