If I'm understanding this correctly (I may not be), you're editing an email template directly in the OpenERP/Odoo interface, but when you try to actually generate an email from the template, the changes aren't present?

We've run into this issue before.  In short - check your translations.  Even if you're not using translations, this can cause the behavior described above in some cases.  For example, in OpenERP v7, duplicating an email template will generate a new translation for the email text in English, even if that's already the system language.  If you don't remove or edit translation, all of the changes you implement will not be visible when the email is generated.

If that's not the issue you're encountering, you'll need to explain in etail what steps you are taking to replicate the issue