vba signatures being discarded
 

i have several excel workgroup templates that contain
macros. i've used selfsign to sign them and all desktops
here have the source as trusted so no one sees the macro
security dialog when the file is opened.

i'm seeing more and more documents prompt users to enable
macros and there isn't the checkbox to set it as a trusted
source. basically, somehow the signatures are being lost.

i've checked and doublechecked. no one is modifying the
macros. what else can cause a signature to be lost? can it
happen just by doing a 'save as' of the workbook? this
seems to be the only thing users are doing... then
updating the content.

is there anything i can do to ensure documents based on my
templates keep their signature as long as no one modifies
the code?

thanks.
ms