Hi Artisan,
This could be because Excel is converting the file into HTML for e-mailing
purposes.
If you are using File, Send To, Mail Recipient from the menu or clicking the
E-mail button, try instead selecting File, Send To, Mail Recipient (as
attachment) instead.
Alternatively try formatting your cells so that a sufficient numer of
decimels are shown. These should be preserved on conversion to HTML.
Hope this helps,
Mark